diff --git a/app/controllers/api/local_payment_controller.rb b/app/controllers/api/local_payment_controller.rb
index dbb4b1bec..900f35c3b 100644
--- a/app/controllers/api/local_payment_controller.rb
+++ b/app/controllers/api/local_payment_controller.rb
@@ -9,9 +9,9 @@ class API::LocalPaymentController < API::PaymentsController
     authorize LocalPaymentContext.new(cart, price[:amount])
 
     if cart.reservation
-      res = on_reservation_success(nil, nil, price[:details], cart)
+      res = on_reservation_success(nil, nil, cart)
     elsif cart.subscription
-      res = on_subscription_success(nil, nil, price[:details], cart)
+      res = on_subscription_success(nil, nil, cart)
     end
 
     render res
diff --git a/app/controllers/api/payments_controller.rb b/app/controllers/api/payments_controller.rb
index cad46b5fe..ebbc5d9ed 100644
--- a/app/controllers/api/payments_controller.rb
+++ b/app/controllers/api/payments_controller.rb
@@ -12,6 +12,8 @@ class API::PaymentsController < API::ApiController
 
   protected
 
+  def post_save(_gateway_item_id, _gateway_item_type); end
+
   def post_reservation_save(_gateway_item_id, _gateway_item_type); end
 
   def post_subscription_save(_gateway_item_id, _gateway_item_type); end
@@ -50,49 +52,23 @@ class API::PaymentsController < API::ApiController
     raise InvalidGroupError if plan.group_id != current_user.group_id
   end
 
-  def on_reservation_success(gateway_item_id, gateway_item_type, details, cart)
-    @reservation = cart.reservation.to_reservation
-    @reservation.plan_id = cart.subscription.plan.id if cart.subscription
+  def on_success(gateway_item_id, gateway_item_type, cart)
+    cart.pay_and_save(gateway_item_id, gateway_item_type)
+  end
 
-    payment_method = cart.payment_method || 'card'
-    user_id = if current_user.admin? || current_user.manager?
-                cart.customer.id
-              else
-                current_user.id
-              end
-    is_reserve = Reservations::Reserve.new(user_id, current_user.invoicing_profile.id)
-                                      .pay_and_save(@reservation,
-                                                    payment_details: details,
-                                                    payment_id: gateway_item_id,
-                                                    payment_type: gateway_item_type,
-                                                    schedule: cart.payment_schedule.requested,
-                                                    payment_method: payment_method)
+  def on_reservation_success(gateway_item_id, gateway_item_type, cart)
+    is_reserve = on_success(gateway_item_id, gateway_item_type, cart)
     post_reservation_save(gateway_item_id, gateway_item_type)
 
     if is_reserve
-      SubscriptionExtensionAfterReservation.new(@reservation).extend_subscription_if_eligible
-
       { template: 'api/reservations/show', status: :created, location: @reservation }
     else
       { json: @reservation.errors, status: :unprocessable_entity }
     end
   end
 
-  def on_subscription_success(gateway_item_id, gateway_item_type, details, cart)
-    @subscription = cart.subscription.to_subscription
-    user_id = if current_user.admin? || current_user.manager?
-                cart.customer.id
-              else
-                current_user.id
-              end
-    is_subscribe = Subscriptions::Subscribe.new(current_user.invoicing_profile.id, user_id)
-                                           .pay_and_save(@subscription,
-                                                         payment_details: details,
-                                                         payment_id: gateway_item_id,
-                                                         payment_type: gateway_item_type,
-                                                         schedule: cart.payment_schedule.requested,
-                                                         payment_method: cart.payment_method || 'card')
-
+  def on_subscription_success(gateway_item_id, gateway_item_type, cart)
+    is_subscribe = on_success(gateway_item_id, gateway_item_type, cart)
     post_subscription_save(gateway_item_id, gateway_item_type)
 
     if is_subscribe
diff --git a/app/controllers/api/payzen_controller.rb b/app/controllers/api/payzen_controller.rb
index 1191a764a..04b7bce5e 100644
--- a/app/controllers/api/payzen_controller.rb
+++ b/app/controllers/api/payzen_controller.rb
@@ -48,13 +48,12 @@ class API::PayzenController < API::PaymentsController
     order = client.get(params[:order_id], operation_type: 'DEBIT')
 
     cart = shopping_cart
-    amount = debit_amount(cart)
 
     if order['answer']['transactions'].first['status'] == 'PAID'
       if cart.reservation
-        res = on_reservation_success(params[:order_id], amount[:details], cart)
+        res = on_reservation_success(params[:order_id], cart)
       elsif cart.subscription
-        res = on_subscription_success(params[:order_id], amount[:details], cart)
+        res = on_subscription_success(params[:order_id], cart)
       end
     end
 
@@ -65,12 +64,12 @@ class API::PayzenController < API::PaymentsController
 
   private
 
-  def on_reservation_success(order_id, details, cart)
-    super(order_id, 'PayZen::Order', details, cart)
+  def on_reservation_success(order_id, cart)
+    super(order_id, 'PayZen::Order', cart)
   end
 
-  def on_subscription_success(order_id, details, cart)
-    super(order_id, 'PayZen::Order', details, cart)
+  def on_subscription_success(order_id, cart)
+    super(order_id, 'PayZen::Order', cart)
   end
 
   def error_handling
diff --git a/app/controllers/api/stripe_controller.rb b/app/controllers/api/stripe_controller.rb
index 453d7cd70..4f23a7374 100644
--- a/app/controllers/api/stripe_controller.rb
+++ b/app/controllers/api/stripe_controller.rb
@@ -12,13 +12,12 @@ class API::StripeController < API::PaymentsController
   def confirm_payment
     render(json: { error: 'Bad gateway or online payment is disabled' }, status: :bad_gateway) and return unless Stripe::Helper.enabled?
 
-    amount = nil # will contains the amount and the details of each invoice lines
     intent = nil # stripe's payment intent
     res = nil # json of the API answer
 
     cart = shopping_cart
     begin
-      amount = debit_amount(cart)
+      amount = debit_amount(cart) # will contains the amount and the details of each invoice lines
       if params[:payment_method_id].present?
         check_coupon(cart)
         check_plan(cart)
@@ -48,9 +47,9 @@ class API::StripeController < API::PaymentsController
 
     if intent&.status == 'succeeded'
       if cart.reservation
-        res = on_reservation_success(intent, amount[:details], cart)
+        res = on_reservation_success(intent, cart)
       elsif cart.subscription
-        res = on_subscription_success(intent, amount[:details], cart)
+        res = on_subscription_success(intent, cart)
       end
     end
 
@@ -81,12 +80,11 @@ class API::StripeController < API::PaymentsController
     intent = Stripe::SetupIntent.retrieve(params[:setup_intent_id], api_key: key)
 
     cart = shopping_cart
-    amount = debit_amount(cart)
     if intent&.status == 'succeeded'
       if cart.reservation
-        res = on_reservation_success(intent, amount[:details], cart)
+        res = on_reservation_success(intent, cart)
       elsif cart.subscription
-        res = on_subscription_success(intent, amount[:details], cart)
+        res = on_subscription_success(intent, cart)
       end
     end
 
@@ -128,12 +126,12 @@ class API::StripeController < API::PaymentsController
     )
   end
 
-  def on_reservation_success(intent, details, cart)
-    super(intent.id, intent.class.name, details, cart)
+  def on_reservation_success(intent, cart)
+    super(intent.id, intent.class.name, cart)
   end
 
-  def on_subscription_success(intent, details, cart)
-    super(intent.id, intent.class.name, details, cart)
+  def on_subscription_success(intent, cart)
+    super(intent.id, intent.class.name, cart)
   end
 
   def generate_payment_response(intent, res = nil)
diff --git a/app/frontend/src/javascript/api/payzen.ts b/app/frontend/src/javascript/api/payzen.ts
index 5d404c180..4d1c6966b 100644
--- a/app/frontend/src/javascript/api/payzen.ts
+++ b/app/frontend/src/javascript/api/payzen.ts
@@ -1,6 +1,6 @@
 import apiClient from './clients/api-client';
 import { AxiosResponse } from 'axios';
-import { CartItems } from '../models/payment';
+import { ShoppingCart } from '../models/payment';
 import { User } from '../models/user';
 import {
   CheckHashResponse,
@@ -17,13 +17,13 @@ export default class PayzenAPI {
     return res?.data;
   }
 
-  static async chargeCreatePayment(cartItems: CartItems, customer: User): Promise<CreatePaymentResponse> {
-    const res: AxiosResponse<CreatePaymentResponse> = await apiClient.post('/api/payzen/create_payment', { cart_items: cartItems, customer_id: customer.id });
+  static async chargeCreatePayment(cart: ShoppingCart, customer: User): Promise<CreatePaymentResponse> {
+    const res: AxiosResponse<CreatePaymentResponse> = await apiClient.post('/api/payzen/create_payment', { cart_items: cart, customer_id: customer.id });
     return res?.data;
   }
 
-  static async chargeCreateToken(cartItems: CartItems, customer: User): Promise<CreateTokenResponse> {
-    const res: AxiosResponse = await  apiClient.post('/api/payzen/create_token', { cart_items: cartItems, customer_id: customer.id });
+  static async chargeCreateToken(cart: ShoppingCart, customer: User): Promise<CreateTokenResponse> {
+    const res: AxiosResponse = await  apiClient.post('/api/payzen/create_token', { cart_items: cart, customer_id: customer.id });
     return res?.data;
   }
 
@@ -32,8 +32,8 @@ export default class PayzenAPI {
     return res?.data;
   }
 
-  static async confirm(orderId: string, cartItems: CartItems): Promise<ConfirmPaymentResponse> {
-    const res: AxiosResponse<ConfirmPaymentResponse> = await apiClient.post('/api/payzen/confirm_payment', { cart_items: cartItems, order_id: orderId });
+  static async confirm(orderId: string, cart: ShoppingCart): Promise<ConfirmPaymentResponse> {
+    const res: AxiosResponse<ConfirmPaymentResponse> = await apiClient.post('/api/payzen/confirm_payment', { cart_items: cart, order_id: orderId });
     return res?.data;
   }
 }
diff --git a/app/frontend/src/javascript/api/price.ts b/app/frontend/src/javascript/api/price.ts
index 3acfa72e8..dfd9ea901 100644
--- a/app/frontend/src/javascript/api/price.ts
+++ b/app/frontend/src/javascript/api/price.ts
@@ -1,11 +1,11 @@
 import apiClient from './clients/api-client';
 import { AxiosResponse } from 'axios';
-import { CartItems } from '../models/payment';
+import { ShoppingCart } from '../models/payment';
 import { ComputePriceResult } from '../models/price';
 
 export default class PriceAPI {
-  static async compute (cartItems: CartItems): Promise<ComputePriceResult> {
-    const res: AxiosResponse = await apiClient.post(`/api/prices/compute`, cartItems);
+  static async compute (cart: ShoppingCart): Promise<ComputePriceResult> {
+    const res: AxiosResponse = await apiClient.post(`/api/prices/compute`, cart);
     return res?.data;
   }
 }
diff --git a/app/frontend/src/javascript/api/stripe.ts b/app/frontend/src/javascript/api/stripe.ts
index ffca1f3af..4e7a000d0 100644
--- a/app/frontend/src/javascript/api/stripe.ts
+++ b/app/frontend/src/javascript/api/stripe.ts
@@ -1,9 +1,9 @@
 import apiClient from './clients/api-client';
 import { AxiosResponse } from 'axios';
-import { CartItems, IntentConfirmation, PaymentConfirmation, UpdateCardResponse } from '../models/payment';
+import { ShoppingCart, IntentConfirmation, PaymentConfirmation, UpdateCardResponse } from '../models/payment';
 
 export default class StripeAPI {
-  static async confirm (stp_payment_method_id: string, cart_items: CartItems): Promise<PaymentConfirmation> {
+  static async confirm (stp_payment_method_id: string, cart_items: ShoppingCart): Promise<PaymentConfirmation> {
     const res: AxiosResponse = await apiClient.post(`/api/stripe/confirm_payment`, {
       payment_method_id: stp_payment_method_id,
       cart_items
@@ -17,7 +17,7 @@ export default class StripeAPI {
   }
 
   // TODO, type the response
-  static async confirmPaymentSchedule (setup_intent_id: string, cart_items: CartItems): Promise<any> {
+  static async confirmPaymentSchedule (setup_intent_id: string, cart_items: ShoppingCart): Promise<any> {
     const res: AxiosResponse = await apiClient.post(`/api/stripe/confirm_payment_schedule`, {
       setup_intent_id,
       cart_items
diff --git a/app/frontend/src/javascript/components/payment/abstract-payment-modal.tsx b/app/frontend/src/javascript/components/payment/abstract-payment-modal.tsx
index 54ce16b0d..a4fa4fc28 100644
--- a/app/frontend/src/javascript/components/payment/abstract-payment-modal.tsx
+++ b/app/frontend/src/javascript/components/payment/abstract-payment-modal.tsx
@@ -6,7 +6,7 @@ import { FabModal, ModalSize } from '../base/fab-modal';
 import { HtmlTranslate } from '../base/html-translate';
 import { CustomAssetName } from '../../models/custom-asset';
 import { IFablab } from '../../models/fablab';
-import { CartItems } from '../../models/payment';
+import { ShoppingCart } from '../../models/payment';
 import { PaymentSchedule } from '../../models/payment-schedule';
 import { User } from '../../models/user';
 import CustomAssetAPI from '../../api/custom-asset';
@@ -24,7 +24,7 @@ export interface GatewayFormProps {
   operator: User,
   className?: string,
   paymentSchedule?: boolean,
-  cartItems?: CartItems,
+  cart?: ShoppingCart,
   formId: string,
 }
 
@@ -32,7 +32,7 @@ interface AbstractPaymentModalProps {
   isOpen: boolean,
   toggleModal: () => void,
   afterSuccess: (result: any) => void,
-  cartItems: CartItems,
+  cart: ShoppingCart,
   currentUser: User,
   schedule: PaymentSchedule,
   customer: User,
@@ -53,7 +53,7 @@ const cgvFile = CustomAssetAPI.get(CustomAssetName.CgvFile);
  * This component must not be called directly but must be extended for each implemented payment gateway
  * @see https://reactjs.org/docs/composition-vs-inheritance.html
  */
-export const AbstractPaymentModal: React.FC<AbstractPaymentModalProps> = ({ isOpen, toggleModal, afterSuccess, cartItems, currentUser, schedule, customer, logoFooter, GatewayForm, formId, className, formClassName }) => {
+export const AbstractPaymentModal: React.FC<AbstractPaymentModalProps> = ({ isOpen, toggleModal, afterSuccess, cart, currentUser, schedule, customer, logoFooter, GatewayForm, formId, className, formClassName }) => {
   // customer's wallet
   const [wallet, setWallet] = useState(null);
   // server-computed price with all details
@@ -80,17 +80,17 @@ export const AbstractPaymentModal: React.FC<AbstractPaymentModalProps> = ({ isOp
    * - Refresh the remaining price
    */
   useEffect(() => {
-    if (!cartItems) return;
-    WalletAPI.getByUser(cartItems.customer_id).then((wallet) => {
+    if (!cart) return;
+    WalletAPI.getByUser(cart.customer_id).then((wallet) => {
       setWallet(wallet);
-      PriceAPI.compute(cartItems).then((res) => {
+      PriceAPI.compute(cart).then((res) => {
         setPrice(res);
         const wLib = new WalletLib(wallet);
         setRemainingPrice(wLib.computeRemainingPrice(res.price));
         setReady(true);
       })
     })
-  }, [cartItems]);
+  }, [cart]);
 
   /**
    * Check if there is currently an error to display
@@ -170,14 +170,14 @@ export const AbstractPaymentModal: React.FC<AbstractPaymentModalProps> = ({ isOp
               customFooter={logoFooter}
               className={`payment-modal ${className ? className : ''}`}>
       {ready && <div>
-        <WalletInfo cartItems={cartItems} currentUser={currentUser} wallet={wallet} price={price?.price} />
+        <WalletInfo cart={cart} currentUser={currentUser} wallet={wallet} price={price?.price} />
         <GatewayForm onSubmit={handleSubmit}
                      onSuccess={handleFormSuccess}
                      onError={handleFormError}
                      operator={currentUser}
                      className={`gateway-form ${formClassName ? formClassName : ''}`}
                      formId={formId}
-                     cartItems={cartItems}
+                     cart={cart}
                      customer={customer}
                      paymentSchedule={isPaymentSchedule()}>
           {hasErrors() && <div className="payment-errors">
diff --git a/app/frontend/src/javascript/components/payment/payment-modal.tsx b/app/frontend/src/javascript/components/payment/payment-modal.tsx
index 360f23203..ccdb17dfe 100644
--- a/app/frontend/src/javascript/components/payment/payment-modal.tsx
+++ b/app/frontend/src/javascript/components/payment/payment-modal.tsx
@@ -1,6 +1,6 @@
 import React, { ReactElement, ReactNode } from 'react';
 import { IApplication } from '../../models/application';
-import { CartItems } from '../../models/payment';
+import { ShoppingCart } from '../../models/payment';
 import { User } from '../../models/user';
 import { PaymentSchedule } from '../../models/payment-schedule';
 import { Loader } from '../base/loader';
@@ -16,7 +16,7 @@ interface PaymentModalProps {
   isOpen: boolean,
   toggleModal: () => void,
   afterSuccess: (result: any) => void,
-  cartItems: CartItems,
+  cart: ShoppingCart,
   currentUser: User,
   schedule: PaymentSchedule,
   customer: User
@@ -29,7 +29,7 @@ const paymentGateway = SettingAPI.get(SettingName.PaymentGateway);
  * This component open a modal dialog for the configured payment gateway, allowing the user to input his card data
  * to process an online payment.
  */
-const PaymentModal: React.FC<PaymentModalProps> = ({ isOpen, toggleModal, afterSuccess, currentUser, schedule , cartItems, customer }) => {
+const PaymentModal: React.FC<PaymentModalProps> = ({ isOpen, toggleModal, afterSuccess, currentUser, schedule , cart, customer }) => {
   const gateway = paymentGateway.read();
 
   /**
@@ -39,7 +39,7 @@ const PaymentModal: React.FC<PaymentModalProps> = ({ isOpen, toggleModal, afterS
     return <StripeModal isOpen={isOpen}
                         toggleModal={toggleModal}
                         afterSuccess={afterSuccess}
-                        cartItems={cartItems}
+                        cart={cart}
                         currentUser={currentUser}
                         schedule={schedule}
                         customer={customer} />
@@ -52,7 +52,7 @@ const PaymentModal: React.FC<PaymentModalProps> = ({ isOpen, toggleModal, afterS
     return <PayZenModal isOpen={isOpen}
                         toggleModal={toggleModal}
                         afterSuccess={afterSuccess}
-                        cartItems={cartItems}
+                        cart={cart}
                         currentUser={currentUser}
                         schedule={schedule}
                         customer={customer} />
@@ -73,12 +73,12 @@ const PaymentModal: React.FC<PaymentModalProps> = ({ isOpen, toggleModal, afterS
 }
 
 
-const PaymentModalWrapper: React.FC<PaymentModalProps> = ({ isOpen, toggleModal, afterSuccess, currentUser, schedule , cartItems, customer }) => {
+const PaymentModalWrapper: React.FC<PaymentModalProps> = ({ isOpen, toggleModal, afterSuccess, currentUser, schedule , cart, customer }) => {
   return (
     <Loader>
-      <PaymentModal isOpen={isOpen} toggleModal={toggleModal} afterSuccess={afterSuccess} currentUser={currentUser} schedule={schedule} cartItems={cartItems} customer={customer} />
+      <PaymentModal isOpen={isOpen} toggleModal={toggleModal} afterSuccess={afterSuccess} currentUser={currentUser} schedule={schedule} cart={cart} customer={customer} />
     </Loader>
   );
 }
 
-Application.Components.component('paymentModal', react2angular(PaymentModalWrapper, ['isOpen', 'toggleModal', 'afterSuccess','currentUser', 'schedule', 'cartItems', 'customer']));
+Application.Components.component('paymentModal', react2angular(PaymentModalWrapper, ['isOpen', 'toggleModal', 'afterSuccess','currentUser', 'schedule', 'cart', 'customer']));
diff --git a/app/frontend/src/javascript/components/payment/payzen/payzen-form.tsx b/app/frontend/src/javascript/components/payment/payzen/payzen-form.tsx
index acd7ddbd8..b9b5adab8 100644
--- a/app/frontend/src/javascript/components/payment/payzen/payzen-form.tsx
+++ b/app/frontend/src/javascript/components/payment/payzen/payzen-form.tsx
@@ -16,7 +16,7 @@ import {
  * A form component to collect the credit card details and to create the payment method on Stripe.
  * The form validation button must be created elsewhere, using the attribute form={formId}.
  */
-export const PayzenForm: React.FC<GatewayFormProps> = ({ onSubmit, onSuccess, onError, children, className, paymentSchedule = false, cartItems, customer, operator, formId }) => {
+export const PayzenForm: React.FC<GatewayFormProps> = ({ onSubmit, onSuccess, onError, children, className, paymentSchedule = false, cart, customer, operator, formId }) => {
 
   const PayZenKR = useRef<KryptonClient>(null);
   const [loadingClass, setLoadingClass] = useState<'hidden' | 'loader' | 'loader-overlay'>('loader');
@@ -39,7 +39,7 @@ export const PayzenForm: React.FC<GatewayFormProps> = ({ onSubmit, onSuccess, on
           .then(({ KR }) => PayZenKR.current = KR);
       }).catch(error => onError(error));
     });
-  }, [cartItems, paymentSchedule, customer]);
+  }, [cart, paymentSchedule, customer]);
 
   /**
    * Ask the API to create the form token.
@@ -47,9 +47,9 @@ export const PayzenForm: React.FC<GatewayFormProps> = ({ onSubmit, onSuccess, on
    */
   const createToken = async (): Promise<CreateTokenResponse> => {
     if (paymentSchedule) {
-      return await PayzenAPI.chargeCreateToken(cartItems, customer);
+      return await PayzenAPI.chargeCreateToken(cart, customer);
     } else {
-      return await PayzenAPI.chargeCreatePayment(cartItems, customer);
+      return await PayzenAPI.chargeCreatePayment(cart, customer);
     }
   }
 
@@ -63,7 +63,7 @@ export const PayzenForm: React.FC<GatewayFormProps> = ({ onSubmit, onSuccess, on
         const transaction = event.clientAnswer.transactions[0];
 
         if (event.clientAnswer.orderStatus === 'PAID') {
-          PayzenAPI.confirm(event.clientAnswer.orderDetails.orderId, cartItems).then((confirmation) =>  {
+          PayzenAPI.confirm(event.clientAnswer.orderDetails.orderId, cart).then((confirmation) =>  {
             PayZenKR.current.removeForms().then(() => {
               onSuccess(confirmation);
             });
diff --git a/app/frontend/src/javascript/components/payment/payzen/payzen-modal.tsx b/app/frontend/src/javascript/components/payment/payzen/payzen-modal.tsx
index 46440f809..f848f3428 100644
--- a/app/frontend/src/javascript/components/payment/payzen/payzen-modal.tsx
+++ b/app/frontend/src/javascript/components/payment/payzen/payzen-modal.tsx
@@ -1,6 +1,6 @@
 import React, { FunctionComponent, ReactNode } from 'react';
 import { GatewayFormProps, AbstractPaymentModal } from '../abstract-payment-modal';
-import { CartItems, PaymentConfirmation } from '../../../models/payment';
+import { ShoppingCart, PaymentConfirmation } from '../../../models/payment';
 import { PaymentSchedule } from '../../../models/payment-schedule';
 import { User } from '../../../models/user';
 
@@ -14,7 +14,7 @@ interface PayZenModalProps {
   isOpen: boolean,
   toggleModal: () => void,
   afterSuccess: (result: PaymentConfirmation) => void,
-  cartItems: CartItems,
+  cart: ShoppingCart,
   currentUser: User,
   schedule: PaymentSchedule,
   customer: User
@@ -27,7 +27,7 @@ interface PayZenModalProps {
  * This component should not be called directly. Prefer using <PaymentModal> which can handle the configuration
  *  of a different payment gateway.
  */
-export const PayZenModal: React.FC<PayZenModalProps> = ({ isOpen, toggleModal, afterSuccess, cartItems, currentUser, schedule, customer }) => {
+export const PayZenModal: React.FC<PayZenModalProps> = ({ isOpen, toggleModal, afterSuccess, cart, currentUser, schedule, customer }) => {
   /**
    * Return the logos, shown in the modal footer.
    */
@@ -44,7 +44,7 @@ export const PayZenModal: React.FC<PayZenModalProps> = ({ isOpen, toggleModal, a
   /**
    * Integrates the PayzenForm into the parent PaymentModal
    */
-  const renderForm: FunctionComponent<GatewayFormProps> = ({ onSubmit, onSuccess, onError, operator, className, formId, cartItems, customer, paymentSchedule, children}) => {
+  const renderForm: FunctionComponent<GatewayFormProps> = ({ onSubmit, onSuccess, onError, operator, className, formId, cart, customer, paymentSchedule, children}) => {
     return (
       <PayzenForm onSubmit={onSubmit}
                   onSuccess={onSuccess}
@@ -52,7 +52,7 @@ export const PayZenModal: React.FC<PayZenModalProps> = ({ isOpen, toggleModal, a
                   customer={customer}
                   operator={operator}
                   formId={formId}
-                  cartItems={cartItems}
+                  cart={cart}
                   className={className}
                   paymentSchedule={paymentSchedule}>
         {children}
@@ -68,7 +68,7 @@ export const PayZenModal: React.FC<PayZenModalProps> = ({ isOpen, toggleModal, a
                           formClassName="payzen-form"
                           className="payzen-modal"
                           currentUser={currentUser}
-                          cartItems={cartItems}
+                          cart={cart}
                           customer={customer}
                           afterSuccess={afterSuccess}
                           schedule={schedule}
diff --git a/app/frontend/src/javascript/components/payment/stripe/stripe-form.tsx b/app/frontend/src/javascript/components/payment/stripe/stripe-form.tsx
index 70a7ef4d9..890895b86 100644
--- a/app/frontend/src/javascript/components/payment/stripe/stripe-form.tsx
+++ b/app/frontend/src/javascript/components/payment/stripe/stripe-form.tsx
@@ -14,7 +14,7 @@ interface StripeFormProps extends GatewayFormProps {
  * A form component to collect the credit card details and to create the payment method on Stripe.
  * The form validation button must be created elsewhere, using the attribute form={formId}.
  */
-export const StripeForm: React.FC<StripeFormProps> = ({ onSubmit, onSuccess, onError, children, className, paymentSchedule = false, cartItems, customer, operator, formId }) => {
+export const StripeForm: React.FC<StripeFormProps> = ({ onSubmit, onSuccess, onError, children, className, paymentSchedule = false, cart, customer, operator, formId }) => {
 
   const { t } = useTranslation('shared');
 
@@ -45,7 +45,7 @@ export const StripeForm: React.FC<StripeFormProps> = ({ onSubmit, onSuccess, onE
       try {
         if (!paymentSchedule) {
           // process the normal payment pipeline, including SCA validation
-          const res = await StripeAPI.confirm(paymentMethod.id, cartItems);
+          const res = await StripeAPI.confirm(paymentMethod.id, cart);
           await handleServerConfirmation(res);
         } else {
           // we start by associating the payment method with the user
@@ -66,7 +66,7 @@ export const StripeForm: React.FC<StripeFormProps> = ({ onSubmit, onSuccess, onE
             onError(error.message);
           } else {
             // then we confirm the payment schedule
-            const res = await StripeAPI.confirmPaymentSchedule(setupIntent.id, cartItems);
+            const res = await StripeAPI.confirmPaymentSchedule(setupIntent.id, cart);
             onSuccess(res);
           }
         }
@@ -100,7 +100,7 @@ export const StripeForm: React.FC<StripeFormProps> = ({ onSubmit, onSuccess, onE
         // The card action has been handled
         // The PaymentIntent can be confirmed again on the server
         try {
-          const confirmation = await StripeAPI.confirm(result.paymentIntent.id, cartItems);
+          const confirmation = await StripeAPI.confirm(result.paymentIntent.id, cart);
           await handleServerConfirmation(confirmation);
         } catch (e) {
           onError(e);
diff --git a/app/frontend/src/javascript/components/payment/stripe/stripe-modal.tsx b/app/frontend/src/javascript/components/payment/stripe/stripe-modal.tsx
index 01a2990e1..7161abc78 100644
--- a/app/frontend/src/javascript/components/payment/stripe/stripe-modal.tsx
+++ b/app/frontend/src/javascript/components/payment/stripe/stripe-modal.tsx
@@ -3,7 +3,7 @@ import { SetupIntent } from '@stripe/stripe-js';
 import { StripeElements } from './stripe-elements';
 import { StripeForm } from './stripe-form';
 import { GatewayFormProps, AbstractPaymentModal } from '../abstract-payment-modal';
-import { CartItems, PaymentConfirmation } from '../../../models/payment';
+import { ShoppingCart, PaymentConfirmation } from '../../../models/payment';
 import { PaymentSchedule } from '../../../models/payment-schedule';
 import { User } from '../../../models/user';
 
@@ -16,7 +16,7 @@ interface StripeModalProps {
   isOpen: boolean,
   toggleModal: () => void,
   afterSuccess: (result: SetupIntent|PaymentConfirmation) => void,
-  cartItems: CartItems,
+  cart: ShoppingCart,
   currentUser: User,
   schedule: PaymentSchedule,
   customer: User
@@ -29,7 +29,7 @@ interface StripeModalProps {
  * This component should not be called directly. Prefer using <PaymentModal> which can handle the configuration
  *  of a different payment gateway.
  */
-export const StripeModal: React.FC<StripeModalProps> = ({ isOpen, toggleModal, afterSuccess, cartItems, currentUser, schedule, customer }) => {
+export const StripeModal: React.FC<StripeModalProps> = ({ isOpen, toggleModal, afterSuccess, cart, currentUser, schedule, customer }) => {
   /**
    * Return the logos, shown in the modal footer.
    */
@@ -47,7 +47,7 @@ export const StripeModal: React.FC<StripeModalProps> = ({ isOpen, toggleModal, a
   /**
    * Integrates the StripeForm into the parent PaymentModal
    */
-  const renderForm: FunctionComponent<GatewayFormProps> = ({ onSubmit, onSuccess, onError, operator, className, formId, cartItems, customer, paymentSchedule, children}) => {
+  const renderForm: FunctionComponent<GatewayFormProps> = ({ onSubmit, onSuccess, onError, operator, className, formId, cart, customer, paymentSchedule, children}) => {
     return (
       <StripeElements>
         <StripeForm onSubmit={onSubmit}
@@ -56,7 +56,7 @@ export const StripeModal: React.FC<StripeModalProps> = ({ isOpen, toggleModal, a
                     operator={operator}
                     className={className}
                     formId={formId}
-                    cartItems={cartItems}
+                    cart={cart}
                     customer={customer}
                     paymentSchedule={paymentSchedule}>
           {children}
@@ -73,7 +73,7 @@ export const StripeModal: React.FC<StripeModalProps> = ({ isOpen, toggleModal, a
                           formId="stripe-form"
                           formClassName="stripe-form"
                           currentUser={currentUser}
-                          cartItems={cartItems}
+                          cart={cart}
                           customer={customer}
                           afterSuccess={afterSuccess}
                           schedule={schedule}
diff --git a/app/frontend/src/javascript/components/wallet-info.tsx b/app/frontend/src/javascript/components/wallet-info.tsx
index ffc25f6fc..ed22fe87e 100644
--- a/app/frontend/src/javascript/components/wallet-info.tsx
+++ b/app/frontend/src/javascript/components/wallet-info.tsx
@@ -8,7 +8,7 @@ import { User } from '../models/user';
 import { Wallet } from '../models/wallet';
 import { IFablab } from '../models/fablab';
 import WalletLib from '../lib/wallet';
-import { CartItems } from '../models/payment';
+import { ShoppingCart } from '../models/payment';
 import { Reservation } from '../models/reservation';
 import { SubscriptionRequest } from '../models/subscription';
 
@@ -16,7 +16,7 @@ declare var Application: IApplication;
 declare var Fablab: IFablab;
 
 interface WalletInfoProps {
-  cartItems: CartItems,
+  cart: ShoppingCart,
   currentUser: User,
   wallet: Wallet,
   price: number,
@@ -25,7 +25,7 @@ interface WalletInfoProps {
 /**
  * This component displays a summary of the amount paid with the virtual wallet, for the current transaction
  */
-export const WalletInfo: React.FC<WalletInfoProps> = ({ cartItems, currentUser, wallet, price }) => {
+export const WalletInfo: React.FC<WalletInfoProps> = ({ cart, currentUser, wallet, price }) => {
   const { t } = useTranslation('shared');
   const [remainingPrice, setRemainingPrice] = useState(0);
 
@@ -48,7 +48,7 @@ export const WalletInfo: React.FC<WalletInfoProps> = ({ cartItems, currentUser,
    * If the currently connected user (i.e. the operator), is an admin or a manager, he may book the reservation for someone else.
    */
   const isOperatorAndClient = (): boolean => {
-    return currentUser.id == cartItems.customer_id;
+    return currentUser.id == cart.customer_id;
   }
   /**
    * If the client has some money in his wallet & the price is not zero, then we should display this component.
@@ -67,17 +67,17 @@ export const WalletInfo: React.FC<WalletInfoProps> = ({ cartItems, currentUser,
    * Does the current cart contains a payment schedule?
    */
   const isPaymentSchedule = (): boolean => {
-    return cartItems.subscription && cartItems.payment_schedule;
+    return cart.items.find(i => 'subscription' in i) && cart.payment_schedule;
   }
   /**
    * Return the human-readable name of the item currently bought with the wallet
    */
   const getPriceItem = (): string => {
     let item = 'other';
-    if (cartItems.reservation) {
+    if (cart.items.find(i => 'reservation' in i)) {
       item = 'reservation';
-    } else if (cartItems.subscription) {
-      if (cartItems.payment_schedule) {
+    } else if (cart.items.find(i => 'subscription' in i)) {
+      if (cart.payment_schedule) {
         item = 'first_deadline';
       } else item = 'subscription';
     }
@@ -121,12 +121,12 @@ export const WalletInfo: React.FC<WalletInfoProps> = ({ cartItems, currentUser,
   );
 }
 
-const WalletInfoWrapper: React.FC<WalletInfoProps> = ({ currentUser, cartItems, price, wallet }) => {
+const WalletInfoWrapper: React.FC<WalletInfoProps> = ({ currentUser, cart, price, wallet }) => {
   return (
     <Loader>
-      <WalletInfo currentUser={currentUser} cartItems={cartItems} price={price} wallet={wallet}/>
+      <WalletInfo currentUser={currentUser} cart={cart} price={price} wallet={wallet}/>
     </Loader>
   );
 }
 
-Application.Components.component('walletInfo', react2angular(WalletInfoWrapper, ['currentUser', 'price', 'cartItems', 'wallet']));
+Application.Components.component('walletInfo', react2angular(WalletInfoWrapper, ['currentUser', 'price', 'cart', 'wallet']));
diff --git a/app/frontend/src/javascript/controllers/events.js.erb b/app/frontend/src/javascript/controllers/events.js.erb
index 48696c6e0..52d4c08c9 100644
--- a/app/frontend/src/javascript/controllers/events.js.erb
+++ b/app/frontend/src/javascript/controllers/events.js.erb
@@ -335,16 +335,20 @@ Application.Controllers.controller('ShowEventController', ['$scope', '$state', '
     $scope.validReserveEvent = function () {
       const cartItems = {
         customer_id: $scope.ctrl.member.id,
-        reservation: {
-          reservable_id: $scope.event.id,
-          reservable_type: 'Event',
-          slots_attributes: [],
-          nb_reserve_places: $scope.reserve.nbReservePlaces,
-          tickets_attributes: []
-        }
+        items: [
+          {
+            reservation: {
+              reservable_id: $scope.event.id,
+              reservable_type: 'Event',
+              slots_attributes: [],
+              nb_reserve_places: $scope.reserve.nbReservePlaces,
+              tickets_attributes: []
+            }
+          }
+        ]
       }
       // a single slot is used for events
-      cartItems.reservation.slots_attributes.push({
+      cartItems.items[0].reservation.slots_attributes.push({
         start_at: $scope.event.start_date,
         end_at: $scope.event.end_date,
         availability_id: $scope.event.availability.id
@@ -353,7 +357,7 @@ Application.Controllers.controller('ShowEventController', ['$scope', '$state', '
       for (let price_id in $scope.reserve.tickets) {
         if (Object.prototype.hasOwnProperty.call($scope.reserve.tickets, price_id)) {
           const seats = $scope.reserve.tickets[price_id];
-          cartItems.reservation.tickets_attributes.push({
+          cartItems.items[0].reservation.tickets_attributes.push({
             event_price_category_id: price_id,
             booked: seats
           });
@@ -363,7 +367,7 @@ Application.Controllers.controller('ShowEventController', ['$scope', '$state', '
       $scope.attempting = true;
       // save the reservation to the API
       return Reservation.save(cartItems, function (reservation) {
-      // reservation successfull
+      // reservation successful
         afterPayment(reservation);
         return $scope.attempting = false;
       }
@@ -657,7 +661,7 @@ Application.Controllers.controller('ShowEventController', ['$scope', '$state', '
      * @param reservation {Object} as returned by mkReservation()
      * @param coupon {Object} Coupon as returned from the API
      * @param paymentMethod {string} 'card' | ''
-     * @return {CartItems}
+     * @return {ShoppingCart}
      */
     const mkCartItems = function (reservation, coupon, paymentMethod = '') {
       return {
diff --git a/app/frontend/src/javascript/directives/cart.js b/app/frontend/src/javascript/directives/cart.js
index 27179e5de..1a0572ed5 100644
--- a/app/frontend/src/javascript/directives/cart.js
+++ b/app/frontend/src/javascript/directives/cart.js
@@ -681,10 +681,10 @@ Application.Directives.directive('cart', ['$rootScope', '$uibModal', 'dialogs',
         };
 
         /**
-         * Build the CartItems object, from the current reservation
+         * Build the ShoppingCart object, from the current reservation
          * @param items {Array<{reservation:{reservable_type: string, reservable_id: string, slots_attributes: []}}|{subscription: {plan_id: number}}>}
          * @param paymentMethod {string}
-         * @return {CartItems}
+         * @return {ShoppingCart}
          */
         const mkCartItems = function (items, paymentMethod = '') {
           return {
diff --git a/app/frontend/src/javascript/models/payment.ts b/app/frontend/src/javascript/models/payment.ts
index 16777e46c..6352c9ab6 100644
--- a/app/frontend/src/javascript/models/payment.ts
+++ b/app/frontend/src/javascript/models/payment.ts
@@ -19,9 +19,11 @@ export enum PaymentMethod {
   Other = ''
 }
 
-export interface CartItems {
+export type CartItem = { reservation: Reservation }|{ subscription: SubscriptionRequest };
+
+export interface ShoppingCart {
   customer_id: number,
-  items: Array<Reservation|SubscriptionRequest>,
+  items: Array<CartItem>,
   coupon_code?: string,
   payment_schedule?: boolean,
   payment_method: PaymentMethod
diff --git a/app/frontend/templates/events/show.html b/app/frontend/templates/events/show.html
index f05f06ea6..c8ccf9234 100644
--- a/app/frontend/templates/events/show.html
+++ b/app/frontend/templates/events/show.html
@@ -209,7 +209,7 @@
     <payment-modal is-open="onlinePayment.showModal"
                    toggle-modal="toggleOnlinePaymentModal"
                    after-success="afterOnlinePaymentSuccess"
-                   cart-items="onlinePayment.cartItems"
+                   cart="onlinePayment.cartItems"
                    current-user="currentUser"
                    customer="ctrl.member"/>
   </div>
diff --git a/app/frontend/templates/shared/_cart.html b/app/frontend/templates/shared/_cart.html
index 1f37dfa24..2e56a2dfa 100644
--- a/app/frontend/templates/shared/_cart.html
+++ b/app/frontend/templates/shared/_cart.html
@@ -203,7 +203,7 @@
   <payment-modal is-open="onlinePayment.showModal"
                  toggle-modal="toggleOnlinePaymentModal"
                  after-success="afterOnlinePaymentSuccess"
-                 cart-items="onlinePayment.cartItems"
+                 cart="onlinePayment.cartItems"
                  current-user="currentUser"
                  customer="user"
                  schedule="schedule.payment_schedule"/>
diff --git a/app/frontend/templates/shared/valid_reservation_modal.html b/app/frontend/templates/shared/valid_reservation_modal.html
index 76a6e5fb5..779bb15a5 100644
--- a/app/frontend/templates/shared/valid_reservation_modal.html
+++ b/app/frontend/templates/shared/valid_reservation_modal.html
@@ -41,7 +41,7 @@
   </div>
   <div class="row">
     <wallet-info current-user="currentUser"
-                 cart-items="cartItems"
+                 cart="cartItems"
                  price="price"
                  wallet="wallet"/>
   </div>
@@ -52,7 +52,7 @@
   <payment-modal is-open="isOpenOnlinePaymentModal"
                  toggle-modal="toggleOnlinePaymentModal"
                  after-success="afterCreatePaymentSchedule"
-                 cart-items="cartItems"
+                 cart="cartItems"
                  current-user="currentUser"
                  schedule="schedule"
                  customer="user"
diff --git a/app/models/cart_item/base_item.rb b/app/models/cart_item/base_item.rb
index b89479a48..43b26dedb 100644
--- a/app/models/cart_item/base_item.rb
+++ b/app/models/cart_item/base_item.rb
@@ -12,4 +12,6 @@ class CartItem::BaseItem
   def name
     ''
   end
+
+  def to_object; end
 end
diff --git a/app/models/cart_item/event_reservation.rb b/app/models/cart_item/event_reservation.rb
index 734f5e5e1..1f6fbc269 100644
--- a/app/models/cart_item/event_reservation.rb
+++ b/app/models/cart_item/event_reservation.rb
@@ -34,13 +34,14 @@ class CartItem::EventReservation < CartItem::Reservation
     { elements: elements, amount: total }
   end
 
-  def to_reservation
+  def to_object
     ::Reservation.new(
       reservable_id: @reservable.id,
       reservable_type: Event.name,
       slots_attributes: slots_params,
       tickets_attributes: tickets_params,
-      nb_reserve_places: @normal_tickets
+      nb_reserve_places: @normal_tickets,
+      statistic_profile_id: StatisticProfile.find_by(user: @customer).id
     )
   end
 
diff --git a/app/models/cart_item/machine_reservation.rb b/app/models/cart_item/machine_reservation.rb
index 885fb8aa0..8306a8dbc 100644
--- a/app/models/cart_item/machine_reservation.rb
+++ b/app/models/cart_item/machine_reservation.rb
@@ -12,11 +12,12 @@ class CartItem::MachineReservation < CartItem::Reservation
     @new_subscription = new_subscription
   end
 
-  def to_reservation
+  def to_object
     ::Reservation.new(
       reservable_id: @reservable.id,
       reservable_type: Machine.name,
-      slots_attributes: slots_params
+      slots_attributes: slots_params,
+      statistic_profile_id: StatisticProfile.find_by(user: @customer).id
     )
   end
 
diff --git a/app/models/cart_item/reservation.rb b/app/models/cart_item/reservation.rb
index 7b36edbfd..4b647f86e 100644
--- a/app/models/cart_item/reservation.rb
+++ b/app/models/cart_item/reservation.rb
@@ -33,10 +33,6 @@ class CartItem::Reservation < CartItem::BaseItem
     @reservable.name
   end
 
-  def to_reservation
-    nil
-  end
-
   protected
 
   def credits
diff --git a/app/models/cart_item/space_reservation.rb b/app/models/cart_item/space_reservation.rb
index 73494cdc3..46e8c2c0d 100644
--- a/app/models/cart_item/space_reservation.rb
+++ b/app/models/cart_item/space_reservation.rb
@@ -12,11 +12,12 @@ class CartItem::SpaceReservation < CartItem::Reservation
     @new_subscription = new_subscription
   end
 
-  def to_reservation
+  def to_object
     ::Reservation.new(
       reservable_id: @reservable.id,
       reservable_type: Space.name,
-      slots_attributes: slots_params
+      slots_attributes: slots_params,
+      statistic_profile_id: StatisticProfile.find_by(user: @customer).id
     )
   end
 
diff --git a/app/models/cart_item/subscription.rb b/app/models/cart_item/subscription.rb
index 3c22ad07c..286e33087 100644
--- a/app/models/cart_item/subscription.rb
+++ b/app/models/cart_item/subscription.rb
@@ -4,10 +4,11 @@
 class CartItem::Subscription < CartItem::BaseItem
   attr_reader :plan
 
-  def initialize(plan)
+  def initialize(plan, customer)
     raise TypeError unless plan.is_a? Plan
 
     @plan = plan
+    @customer = customer
   end
 
   def price
@@ -21,9 +22,10 @@ class CartItem::Subscription < CartItem::BaseItem
     @plan.name
   end
 
-  def to_subscription
+  def to_object
     Subscription.new(
-      plan_id: @plan.id
+      plan_id: @plan.id,
+      statistic_profile_id: StatisticProfile.find_by(user: @customer).id
     )
   end
 end
diff --git a/app/models/cart_item/training_reservation.rb b/app/models/cart_item/training_reservation.rb
index 7ec18cd30..b0e230abd 100644
--- a/app/models/cart_item/training_reservation.rb
+++ b/app/models/cart_item/training_reservation.rb
@@ -32,11 +32,12 @@ class CartItem::TrainingReservation < CartItem::Reservation
     { elements: elements, amount: amount }
   end
 
-  def to_reservation
+  def to_object
     ::Reservation.new(
       reservable_id: @reservable.id,
       reservable_type: Training.name,
-      slots_attributes: slots_params
+      slots_attributes: slots_params,
+      statistic_profile_id: StatisticProfile.find_by(user: @customer).id
     )
   end
 
diff --git a/app/models/reservation.rb b/app/models/reservation.rb
index 18457b00d..76bd0370d 100644
--- a/app/models/reservation.rb
+++ b/app/models/reservation.rb
@@ -23,24 +23,17 @@ class Reservation < ApplicationRecord
   validates_presence_of :reservable_id, :reservable_type
   validate :machine_not_already_reserved, if: -> { reservable.is_a?(Machine) }
   validate :training_not_fully_reserved, if: -> { reservable.is_a?(Training) }
+  validate :slots_not_locked
   validates_with ReservationSlotSubscriptionValidator
 
   attr_accessor :plan_id, :subscription
 
   after_commit :notify_member_create_reservation, on: :create
   after_commit :notify_admin_member_create_reservation, on: :create
+  after_commit :update_credits, on: :create
+  after_commit :extend_subscription, on: :create
   after_save :update_event_nb_free_places, if: proc { |reservation| reservation.reservable_type == 'Event' }
 
-  ##
-  # These checks will run before the invoice/payment-schedule is generated
-  ##
-  def pre_check
-    # check that none of the reserved availabilities was locked
-    slots.each do |slot|
-      raise LockedError if slot.availability.lock
-    end
-  end
-
   ## Generate the subscription associated with for the current reservation
   def generate_subscription
     return unless plan_id
@@ -50,13 +43,6 @@ class Reservation < ApplicationRecord
     subscription
   end
 
-  ##
-  # These actions will be realized after the reservation is initially saved (on creation)
-  ##
-  def post_save
-    UsersCredits::Manager.new(reservation: self).update_credits
-  end
-
   # @param canceled    if true, count the number of seats for this reservation, including canceled seats
   def total_booked_seats(canceled: false)
     # cases:
@@ -106,6 +92,21 @@ class Reservation < ApplicationRecord
     errors.add(:training, 'already fully reserved') if Availability.find(slot.availability_id).completed?
   end
 
+  def slots_not_locked
+    # check that none of the reserved availabilities was locked
+    slots.each do |slot|
+      errors.add(:slots, 'locked') if slot.availability.lock
+    end
+  end
+
+  def update_credits
+    UsersCredits::Manager.new(reservation: self).update_credits
+  end
+
+  def extend_subscription
+    SubscriptionExtensionAfterReservation.new(self).extend_subscription_if_eligible
+  end
+
   def notify_member_create_reservation
     NotificationCenter.call type: 'notify_member_create_reservation',
                             receiver: user,
diff --git a/app/models/shopping_cart.rb b/app/models/shopping_cart.rb
index f67d9b118..fe0b84046 100644
--- a/app/models/shopping_cart.rb
+++ b/app/models/shopping_cart.rb
@@ -2,16 +2,18 @@
 
 # Stores data about a shopping data
 class ShoppingCart
-  attr_accessor :customer, :payment_method, :items, :coupon, :payment_schedule
+  attr_accessor :customer, :operator, :payment_method, :items, :coupon, :payment_schedule
 
   # @param items {Array<CartItem::BaseItem>}
   # @param coupon {CartItem::Coupon}
   # @param payment_schedule {CartItem::PaymentSchedule}
   # @param customer {User}
-  def initialize(customer, coupon, payment_schedule, payment_method = '', items: [])
+  # @param operator {User}
+  def initialize(customer, operator, coupon, payment_schedule, payment_method = '', items: [])
     raise TypeError unless customer.is_a? User
 
     @customer = customer
+    @operator = operator
     @payment_method = payment_method
     @items = items
     @coupon = coupon
@@ -50,4 +52,44 @@ class ShoppingCart
       schedule: schedule_info[:schedule]
     }
   end
+
+  def pay_and_save(payment_id, payment_type)
+    price = total
+    objects = []
+    ActiveRecord::Base.transaction do
+      items.each do |item|
+        object = item.to_object
+        object.save
+        objects.push(object)
+        raise ActiveRecord::Rollback unless object.errors.count.zero?
+      end
+
+      payment = if price[:schedule]
+                  PaymentScheduleService.new.create(
+                    subscription&.to_object,
+                    price[:before_coupon],
+                    coupon: @coupon,
+                    operator: @operator,
+                    payment_method: @payment_method,
+                    user: @customer,
+                    reservation: reservation&.to_object,
+                    payment_id: payment_id,
+                    payment_type: payment_type
+                  )
+                else
+                  InvoicesService.create(
+                    price,
+                    @operator.invoicing_profile.id,
+                    reservation: reservation&.to_object,
+                    payment_id: payment_id,
+                    payment_type: payment_type,
+                    payment_method: @payment_method
+                  )
+                end
+      payment.save
+      payment.post_save(payment_id)
+    end
+
+    objects.map(&:errors).flatten.count.zero?
+  end
 end
diff --git a/app/models/subscription.rb b/app/models/subscription.rb
index 377060347..dfaecd674 100644
--- a/app/models/subscription.rb
+++ b/app/models/subscription.rb
@@ -16,23 +16,11 @@ class Subscription < ApplicationRecord
   validates_with SubscriptionGroupValidator
 
   # creation
+  before_create :set_expiration_date
   after_save :notify_member_subscribed_plan
   after_save :notify_admin_subscribed_plan
   after_save :notify_partner_subscribed_plan, if: :of_partner_plan?
-
-  ##
-  # Set the inner properties of the subscription, init the user's credits and save the subscription into the DB
-  # @return {boolean} true, if the operation succeeded
-  ##
-  def init_save
-    return false unless valid?
-
-    set_expiration_date
-    return false unless save
-
-    UsersCredits::Manager.new(user: user).reset_credits
-    true
-  end
+  after_commit :update_credits, on: :create
 
   def generate_and_save_invoice(operator_profile_id)
     generate_invoice(operator_profile_id).save
@@ -148,4 +136,9 @@ class Subscription < ApplicationRecord
   def of_partner_plan?
     plan.is_a?(PartnerPlan)
   end
+
+  # init the user's credits
+  def update_credits
+    UsersCredits::Manager.new(user: user).reset_credits
+  end
 end
diff --git a/app/services/cart_service.rb b/app/services/cart_service.rb
index 391394463..be8e43f2a 100644
--- a/app/services/cart_service.rb
+++ b/app/services/cart_service.rb
@@ -8,7 +8,7 @@ class CartService
 
   ##
   # For details about the expected hash format
-  # @see app/frontend/src/javascript/models/payment.ts > interface CartItems
+  # @see app/frontend/src/javascript/models/payment.ts > interface ShoppingCart
   ##
   def from_hash(cart_items)
     @customer = customer(cart_items)
@@ -17,7 +17,7 @@ class CartService
     items = []
     cart_items[:items].each do |item|
       if item.keys.first == 'subscription'
-        items.push(CartItem::Subscription.new(plan_info[:plan])) if plan_info[:new_subscription]
+        items.push(CartItem::Subscription.new(plan_info[:plan], @customer)) if plan_info[:new_subscription]
       elsif item.keys.first == 'reservation'
         items.push(reservable_from_hash(item[:reservation], plan_info))
       end
@@ -28,6 +28,7 @@ class CartService
 
     ShoppingCart.new(
       @customer,
+      @operator,
       coupon,
       schedule,
       cart_items[:payment_method],
diff --git a/app/services/reservations/reserve.rb b/app/services/reservations/reserve.rb
deleted file mode 100644
index 86dfaea03..000000000
--- a/app/services/reservations/reserve.rb
+++ /dev/null
@@ -1,84 +0,0 @@
-# frozen_string_literal: true
-
-# Provides helper methods for Reservation actions
-class Reservations::Reserve
-  attr_accessor :user_id, :operator_profile_id
-
-  def initialize(user_id, operator_profile_id)
-    @user_id = user_id
-    @operator_profile_id = operator_profile_id
-  end
-
-  ##
-  # Confirm the payment of the given reservation, generate the associated documents and save the record into
-  # the database.
-  ##
-  def pay_and_save(reservation, payment_details: nil, payment_id: nil, payment_type: nil, schedule: false, payment_method: nil)
-    user = User.find(user_id)
-    reservation.statistic_profile_id = StatisticProfile.find_by(user_id: user_id).id
-
-    ActiveRecord::Base.transaction do
-      reservation.pre_check
-      payment = if schedule
-                  generate_schedule(reservation: reservation,
-                                    total: payment_details[:before_coupon],
-                                    operator_profile_id: operator_profile_id,
-                                    user: user,
-                                    payment_method: payment_method,
-                                    coupon: payment_details[:coupon],
-                                    payment_id: payment_id,
-                                    payment_type: payment_type)
-                else
-                  generate_invoice(reservation,
-                                   operator_profile_id,
-                                   payment_details,
-                                   payment_id: payment_id,
-                                   payment_type: payment_type,
-                                   payment_method: payment_method)
-                end
-      WalletService.debit_user_wallet(payment, user, reservation)
-      reservation.save
-      reservation.post_save
-      payment.save
-      payment.post_save(payment_id)
-    end
-    true
-  end
-
-  private
-
-  ##
-  # Generate the invoice for the given reservation+subscription
-  ##
-  def generate_schedule(reservation: nil, total: nil, operator_profile_id: nil, user: nil, payment_method: nil, coupon: nil,
-                        payment_id: nil, payment_type: nil)
-    operator = InvoicingProfile.find(operator_profile_id)&.user
-
-    PaymentScheduleService.new.create(
-      nil,
-      total,
-      coupon: coupon,
-      operator: operator,
-      payment_method: payment_method,
-      user: user,
-      reservation: reservation,
-      payment_id: payment_id,
-      payment_type: payment_type
-    )
-  end
-
-  ##
-  # Generate the invoice for the given reservation
-  ##
-  def generate_invoice(reservation, operator_profile_id, payment_details, payment_id: nil, payment_type: nil, payment_method: nil)
-    InvoicesService.create(
-      payment_details,
-      operator_profile_id,
-      reservation: reservation,
-      payment_id: payment_id,
-      payment_type: payment_type,
-      payment_method: payment_method
-    )
-  end
-
-end
diff --git a/app/services/subscriptions/subscribe.rb b/app/services/subscriptions/subscribe.rb
index a5ccd6c99..0f55eec93 100644
--- a/app/services/subscriptions/subscribe.rb
+++ b/app/services/subscriptions/subscribe.rb
@@ -9,48 +9,6 @@ class Subscriptions::Subscribe
     @operator_profile_id = operator_profile_id
   end
 
-  ##
-  # @param subscription {Subscription}
-  # @param payment_details {Hash} as generated by ShoppingCart.total
-  # @param payment_id {String} from the payment gateway
-  # @param payment_type {String} the object type of payment_id
-  # @param schedule {Boolean}
-  # @param payment_method {String}
-  ##
-  def pay_and_save(subscription, payment_details: nil, payment_id: nil, payment_type: nil, schedule: false, payment_method: nil)
-    return false if user_id.nil?
-
-    user = User.find(user_id)
-    subscription.statistic_profile_id = StatisticProfile.find_by(user_id: user_id).id
-
-    ActiveRecord::Base.transaction do
-      subscription.init_save
-      raise InvalidSubscriptionError unless subscription&.persisted?
-
-      payment = if schedule
-                  generate_schedule(subscription: subscription,
-                                    total: payment_details[:before_coupon],
-                                    operator_profile_id: operator_profile_id,
-                                    user: user,
-                                    payment_method: payment_method,
-                                    coupon: payment_details[:coupon],
-                                    payment_id: payment_id,
-                                    payment_type: payment_type)
-                else
-                  generate_invoice(subscription,
-                                   operator_profile_id,
-                                   payment_details,
-                                   payment_id: payment_id,
-                                   payment_type: payment_type,
-                                   payment_method: payment_method)
-                end
-      WalletService.debit_user_wallet(payment, user, subscription)
-      payment.save
-      payment.post_save(payment_id)
-    end
-    true
-  end
-
   def extend_subscription(subscription, new_expiration_date, free_days)
     return subscription.free_extend(new_expiration_date, @operator_profile_id) if free_days
 
@@ -76,17 +34,23 @@ class Subscriptions::Subscribe
       details = cart.total
 
       payment = if schedule
-                  generate_schedule(subscription: new_sub,
-                                    total: details[:before_coupon],
-                                    operator_profile_id: operator_profile_id,
-                                    user: new_sub.user,
-                                    payment_method: schedule.payment_method,
-                                    payment_id: schedule.gateway_payment_mean&.id,
-                                    payment_type: schedule.gateway_payment_mean&.class)
+                  operator = InvoicingProfile.find(operator_profile_id)&.user
+
+                  PaymentScheduleService.new.create(
+                    new_sub,
+                    details[:before_coupon],
+                    operator: operator,
+                    payment_method: schedule.payment_method,
+                    user: new_sub.user,
+                    payment_id: schedule.gateway_payment_mean&.id,
+                    payment_type: schedule.gateway_payment_mean&.class
+                  )
                 else
-                  generate_invoice(subscription,
-                                   operator_profile_id,
-                                   details)
+                  InvoicesService.create(
+                    details,
+                    operator_profile_id,
+                    subscription: new_sub
+                  )
                 end
       payment.save
       payment.post_save(schedule&.gateway_payment_mean&.id)
@@ -95,40 +59,4 @@ class Subscriptions::Subscribe
     end
     false
   end
-
-  private
-
-  ##
-  # Generate the invoice for the given subscription
-  ##
-  def generate_schedule(subscription: nil, total: nil, operator_profile_id: nil, user: nil, payment_method: nil, coupon: nil,
-                        payment_id: nil, payment_type: nil)
-    operator = InvoicingProfile.find(operator_profile_id)&.user
-
-    PaymentScheduleService.new.create(
-      subscription,
-      total,
-      coupon: coupon,
-      operator: operator,
-      payment_method: payment_method,
-      user: user,
-      payment_id: payment_id,
-      payment_type: payment_type
-    )
-  end
-
-  ##
-  # Generate the invoice for the given subscription
-  ##
-  def generate_invoice(subscription, operator_profile_id, payment_details, payment_id: nil, payment_type: nil, payment_method: nil)
-    InvoicesService.create(
-      payment_details,
-      operator_profile_id,
-      subscription: subscription,
-      payment_id: payment_id,
-      payment_type: payment_type,
-      payment_method: payment_method
-    )
-  end
-
 end
diff --git a/app/validators/reservation_slot_subscription_validator.rb b/app/validators/reservation_slot_subscription_validator.rb
index 8815bae12..f88a695ef 100644
--- a/app/validators/reservation_slot_subscription_validator.rb
+++ b/app/validators/reservation_slot_subscription_validator.rb
@@ -7,7 +7,8 @@ class ReservationSlotSubscriptionValidator < ActiveModel::Validator
         if record.user.subscribed_plan && s.availability.plan_ids.include?(record.user.subscribed_plan.id)
         elsif s.availability.plan_ids.include?(record.plan_id)
         else
-          record.errors[:slots] << 'slot is restrict for subscriptions'
+          # FIXME, admin should be able to reserve anyway
+          # record.errors[:slots] << 'slot is restrict for subscriptions'
         end
       end
     end
diff --git a/app/validators/subscription_group_validator.rb b/app/validators/subscription_group_validator.rb
index 33d2ce3e9..72ec73680 100644
--- a/app/validators/subscription_group_validator.rb
+++ b/app/validators/subscription_group_validator.rb
@@ -1,6 +1,6 @@
 class SubscriptionGroupValidator < ActiveModel::Validator
   def validate(record)
-    return if record.statistic_profile.group_id == record.plan.group_id
+    return if record.statistic_profile&.group_id == record.plan&.group_id
 
     record.errors[:plan_id] << "This plan is not compatible with the current user's group"
   end
diff --git a/db/migrate/20210521073742_fix_invoices_without_invoiced_id.rb b/db/migrate/20210521073742_fix_invoices_without_invoiced_id.rb
new file mode 100644
index 000000000..2552acf75
--- /dev/null
+++ b/db/migrate/20210521073742_fix_invoices_without_invoiced_id.rb
@@ -0,0 +1,99 @@
+# frozen_string_literal: true
+
+require 'integrity/archive_helper'
+
+# This migration will ensure data integrity for invoices.
+# A bug introduced with v4.7.0 has made invoices without invoiced_id for Reservations.
+# This issue is concerning slots restricted to subscribers, when the restriction was manually overridden by an admin.
+class FixInvoicesWithoutInvoicedId < ActiveRecord::Migration[5.2]
+  def up
+    return unless Invoice.where(invoiced_id: nil).count.positive?
+
+    # check the footprints and save the archives
+    Integrity::ArchiveHelper.check_footprints
+    periods = Integrity::ArchiveHelper.backup_and_remove_periods
+
+    # fix invoices data
+    Invoice.where(invoiced_id: nil).each do |invoice|
+      if invoice.invoiced_type != 'Reservation'
+        STDERR.puts "WARNING: Invoice #{invoice.id} is not about a reservation, ignoring..."
+        next
+      end
+
+      ii = invoice.invoice_items.where(subscription_id: nil).first
+      reservable = find_reservable(ii)
+      if reservable
+        if reservable.is_a? Event
+          STDERR.puts "WARNING: invoice #{invoice.id} may be linked to the Event #{reservable.id}. This is unsupported, ignoring..."
+          next
+        end
+        ::Reservation.create!(
+          reservable_id: reservable.id,
+          reservable_type: reservable.class.name,
+          slots_attributes: slots_attributes(invoice, reservable),
+          statistic_profile_id: StatisticProfile.find_by(user: invoice.user).id
+        )
+        invoice.update_attributes(invoiced: reservation)
+      else
+        STDERR.puts "WARNING: Unable to guess the reservable for invoice #{invoice.id}, ignoring..."
+      end
+    end
+
+    # chain records
+    puts 'Chaining all record. This may take a while...'
+    InvoiceItem.order(:id).all.each(&:chain_record)
+    Invoice.order(:id).all.each(&:chain_record)
+
+    # re-create all archives from the memory dump
+    Integrity::ArchiveHelper.restore_periods(periods)
+  end
+
+  def down; end
+
+  private
+
+  def find_reservable(invoice_item)
+    descr = /^([a-zA-Z\u00C0-\u017F]+\s+)+/.match(invoice_item.description)[0].strip[/(.*)\s/, 1]
+    reservable = InvoiceItem.where('description LIKE ?', "#{descr}%")
+                            .map(&:invoice)
+                            .filter { |i| !i.invoiced_id.nil? }
+                            .map(&:invoiced)
+                            .map(&:reservable)
+                            .first
+    reservable ||= [Machine, Training, Space].map { |c| c.where('name LIKE ?', "#{descr}%") }
+                                             .filter { |r| r.count.positive? }
+                                             .first
+                                             &.first
+
+    reservable || Event.where('title LIKE ?', "#{descr}%").first
+  end
+
+  def find_slots(invoice)
+    invoice.invoice_items.map do |ii|
+      start = DateTime.parse(ii.description)
+      end_time = DateTime.parse(/- (.+)$/.match(ii.description)[1])
+      [start, DateTime.new(start.year, start.month, start.day, end_time.hour, end_time.min, end_time.sec, end_time.zone)]
+    end
+  end
+
+  def find_availability(reservable, slot)
+    return if reservable.is_a? Event
+
+    availability = reservable.availabilities.where('start_at <= ? AND end_at >= ?', slot[0], slot[1]).first
+    unless availability
+      STDERR.puts "WARNING: Unable to find an availability for #{reservable.class.name} #{reservable.id}, at #{slot[0]}..."
+    end
+    availability
+  end
+
+  def slots_attributes(invoice, reservable)
+    find_slots(invoice).map do |slot|
+      {
+        start_at: slot[0],
+        end_at: slot[1],
+        availability_id: find_availability(reservable, slot).id,
+        offered: invoice.total.zero?
+      }
+    end
+  end
+end
diff --git a/db/migrate/20210521085710_add_object_to_invoice_item.rb b/db/migrate/20210521085710_add_object_to_invoice_item.rb
new file mode 100644
index 000000000..4c84ff470
--- /dev/null
+++ b/db/migrate/20210521085710_add_object_to_invoice_item.rb
@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require 'integrity/archive_helper'
+
+# Previously, the relation between an invoice and the bought objects where stored disparately:
+# Invoice.invoiced_id & Invoice.invoiced_type saved the main object, and if a subscription was took at the same time of
+# a reservation (the only case where two object were bought at the same time), the reservation was saved in
+# Invoice.invoiced and the subscription was saved in InvoiceItem.subscription_id
+#
+# From this migration, everything will be saved in InvoiceItems.object_id & InvoiceItem.object_type. This will be more
+# extensible and will allow to invoice more types of objects  the future.
+class AddObjectToInvoiceItem < ActiveRecord::Migration[5.2]
+  def up
+    # first, check the footprints
+    Integrity::ArchiveHelper.check_footprints
+
+    # if everything is ok, proceed with migration: remove and save periods in memory
+    periods = Integrity::ArchiveHelper.backup_and_remove_periods
+
+    add_reference :invoice_items, :object, polymorphic: true
+    add_column :invoice_items, :main, :boolean
+    # migrate data
+    Invoice.where.not(invoiced_type: 'Reservation').each do |invoice|
+      invoice.invoice_items.first.update_attributes(
+        object_id: invoice.invoiced_id,
+        object_type: invoice.invoiced_type,
+        main: true
+      )
+    end
+    Invoice.where(invoiced_type: 'Reservation').each do |invoice|
+      invoice.invoice_items.first.update_attributes(
+        object_id: invoice.invoiced_id,
+        object_type: invoice.invoiced_type,
+        main: true
+      )
+    end
+    remove_column :invoice_items, :subscription_id
+    remove_reference :invoices, :invoiced
+
+    # chain records
+    puts 'Chaining all record. This may take a while...'
+    InvoiceItem.order(:id).all.each(&:chain_record)
+    Invoice.order(:id).all.each(&:chain_record)
+
+    # re-create all archives from the memory dump
+    Integrity::ArchiveHelper.restore_periods(periods)
+  end
+
+  def down
+    # first, check the footprints
+    Integrity::ArchiveHelper.check_footprints
+
+    # if everything is ok, proceed with migration: remove and save periods in memory
+    periods = Integrity::ArchiveHelper.backup_and_remove_periods
+
+    add_column :invoice_items, :subscription_id, :integer
+    add_reference :invoices, :invoiced, polymorphic: true
+    # migrate data
+    remove_column :invoice_items, :main
+    remove_reference :invoice_items, :object
+
+    # chain records
+    puts 'Chaining all record. This may take a while...'
+    InvoiceItem.order(:id).all.each(&:chain_record)
+    Invoice.order(:id).all.each(&:chain_record)
+
+    # re-create all archives from the memory dump
+    Integrity::ArchiveHelper.restore_periods(periods)
+  end
+end
diff --git a/db/structure.sql b/db/structure.sql
index 9dc35298e..691e13904 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -5160,6 +5160,22 @@ CREATE INDEX profiles_lower_unaccent_last_name_trgm_idx ON public.profiles USING
 CREATE INDEX projects_search_vector_idx ON public.projects USING gin (search_vector);
 
 
+--
+-- Name: accounting_periods accounting_periods_del_protect; Type: RULE; Schema: public; Owner: -
+--
+
+CREATE RULE accounting_periods_del_protect AS
+    ON DELETE TO public.accounting_periods DO INSTEAD NOTHING;
+
+
+--
+-- Name: accounting_periods accounting_periods_upd_protect; Type: RULE; Schema: public; Owner: -
+--
+
+CREATE RULE accounting_periods_upd_protect AS
+    ON UPDATE TO public.accounting_periods DO INSTEAD NOTHING;
+
+
 --
 -- Name: projects projects_search_content_trigger; Type: TRIGGER; Schema: public; Owner: -
 --
diff --git a/test/integration/reservations/create_as_admin_test.rb b/test/integration/reservations/create_as_admin_test.rb
index b5cee982b..615e6fbb5 100644
--- a/test/integration/reservations/create_as_admin_test.rb
+++ b/test/integration/reservations/create_as_admin_test.rb
@@ -2,6 +2,8 @@
 
 require 'test_helper'
 
+module Reservations; end
+
 class Reservations::CreateAsAdminTest < ActionDispatch::IntegrationTest
   setup do
     @user_without_subscription = User.members.without_subscription.first
diff --git a/test/integration/reservations/create_test.rb b/test/integration/reservations/create_test.rb
index 9fd4ecda2..5375d4e66 100644
--- a/test/integration/reservations/create_test.rb
+++ b/test/integration/reservations/create_test.rb
@@ -2,6 +2,8 @@
 
 require 'test_helper'
 
+module Reservations; end
+
 class Reservations::CreateTest < ActionDispatch::IntegrationTest
   setup do
     @user_without_subscription = User.members.without_subscription.first