diff --git a/app/controllers/api/cart_controller.rb b/app/controllers/api/cart_controller.rb
index c9de2170d..82cc48615 100644
--- a/app/controllers/api/cart_controller.rb
+++ b/app/controllers/api/cart_controller.rb
@@ -31,6 +31,12 @@ class API::CartController < API::ApiController
     render 'api/orders/show'
   end
 
+  def set_offer
+    authorize @current_order, policy_class: CartPolicy
+    @order = Cart::SetOfferService.new.call(@current_order, orderable, cart_params[:is_offered])
+    render 'api/orders/show'
+  end
+
   private
 
   def orderable
diff --git a/app/controllers/api/coupons_controller.rb b/app/controllers/api/coupons_controller.rb
index 3d7b37703..8081a7bf7 100644
--- a/app/controllers/api/coupons_controller.rb
+++ b/app/controllers/api/coupons_controller.rb
@@ -3,7 +3,7 @@
 # API Controller for resources of type Coupon
 # Coupons are used in payments
 class API::CouponsController < API::ApiController
-  before_action :authenticate_user!
+  before_action :authenticate_user!, except: %i[validate]
   before_action :set_coupon, only: %i[show update destroy]
 
   # Number of notifications added to the page when the user clicks on 'load next notifications'
@@ -31,18 +31,18 @@ class API::CouponsController < API::ApiController
     if @coupon.nil?
       render json: { status: 'rejected' }, status: :not_found
     else
-      _user_id = if !current_user.admin?
-                   current_user.id
-                 else
+      _user_id = if current_user&.admin?
                    params[:user_id]
+                 else
+                   current_user&.id
                  end
 
       amount = params[:amount].to_f * 100.0
       status = @coupon.status(_user_id, amount)
-      if status != 'active'
-        render json: { status: status }, status: :unprocessable_entity
-      else
+      if status == 'active'
         render :validate, status: :ok, location: @coupon
+      else
+        render json: { status: status }, status: :unprocessable_entity
       end
     end
   end
diff --git a/app/controllers/concerns/api/order_concern.rb b/app/controllers/concerns/api/order_concern.rb
index 9e14854dd..6c0b753c1 100644
--- a/app/controllers/concerns/api/order_concern.rb
+++ b/app/controllers/concerns/api/order_concern.rb
@@ -17,6 +17,6 @@ module API::OrderConcern
   end
 
   def cart_params
-    params.permit(:order_token, :orderable_id, :quantity, :user_id)
+    params.permit(:order_token, :orderable_id, :quantity, :user_id, :is_offered)
   end
 end
diff --git a/app/frontend/src/javascript/api/cart.ts b/app/frontend/src/javascript/api/cart.ts
index 4601de322..f0efea8db 100644
--- a/app/frontend/src/javascript/api/cart.ts
+++ b/app/frontend/src/javascript/api/cart.ts
@@ -22,4 +22,9 @@ export default class CartAPI {
     const res: AxiosResponse<Order> = await apiClient.put('/api/cart/set_quantity', { order_token: order.token, orderable_id: orderableId, quantity });
     return res?.data;
   }
+
+  static async setOffer (order: Order, orderableId: number, isOffered: boolean): Promise<Order> {
+    const res: AxiosResponse<Order> = await apiClient.put('/api/cart/set_offer', { order_token: order.token, orderable_id: orderableId, is_offered: isOffered });
+    return res?.data;
+  }
 }
diff --git a/app/frontend/src/javascript/components/cart/cart-button.tsx b/app/frontend/src/javascript/components/cart/cart-button.tsx
index 959342044..b9e2b3029 100644
--- a/app/frontend/src/javascript/components/cart/cart-button.tsx
+++ b/app/frontend/src/javascript/components/cart/cart-button.tsx
@@ -22,13 +22,15 @@ const CartButton: React.FC = () => {
    * Goto cart page
    */
   const showCart = () => {
-    window.location.href = '/#!/cart';
+    window.location.href = '/#!/store/cart';
   };
 
   return (
     <div className="cart-button" onClick={showCart}>
       <i className="fas fa-cart-arrow-down" />
-      <span>{cart?.order_items_attributes?.length}</span>
+      {cart && cart.order_items_attributes.length > 0 &&
+        <span>{cart.order_items_attributes.length}</span>
+      }
       <p>{t('app.public.cart_button.my_cart')}</p>
     </div>
   );
diff --git a/app/frontend/src/javascript/components/cart/store-cart.tsx b/app/frontend/src/javascript/components/cart/store-cart.tsx
index a345a8b2d..f385d3821 100644
--- a/app/frontend/src/javascript/components/cart/store-cart.tsx
+++ b/app/frontend/src/javascript/components/cart/store-cart.tsx
@@ -115,8 +115,12 @@ const StoreCart: React.FC<StoreCartProps> = ({ onSuccess, onError, currentUser,
   /**
    * Toggle product offer
    */
-  const onSwitch = (product, checked: boolean) => {
-    console.log('Offer ', product.orderable_name, ': ', checked);
+  const toogleProductOffer = (item) => {
+    return (checked: boolean) => {
+      CartAPI.setOffer(cart, item.orderable_id, checked).then(data => {
+        setCart(data);
+      }).catch(onError);
+    };
   };
 
   /**
@@ -128,14 +132,50 @@ const StoreCart: React.FC<StoreCartProps> = ({ onSuccess, onError, currentUser,
     }
   };
 
+  /**
+   * Get the item total
+   */
+  const itemAmount = (item): number => {
+    return item.quantity * Math.trunc(item.amount * 100) / 100;
+  };
+
+  /**
+   * return true if cart has offered item
+   */
+  const hasOfferedItem = (): boolean => {
+    return cart.order_items_attributes
+      .filter(i => i.is_offered).length > 0;
+  };
+
   /**
    * Get the offered item total
    */
   const offeredAmount = (): number => {
     return cart.order_items_attributes
       .filter(i => i.is_offered)
-      .map(i => i.amount)
-      .reduce((acc, curr) => acc + curr, 0);
+      .map(i => Math.trunc(i.amount * 100) * i.quantity)
+      .reduce((acc, curr) => acc + curr, 0) / 100;
+  };
+
+  /**
+   * Get the total amount before offered amount
+   */
+  const totalBeforeOfferedAmount = (): number => {
+    return (Math.trunc(cart.total * 100) + Math.trunc(offeredAmount() * 100)) / 100;
+  };
+
+  /**
+   * Get the coupon amount
+   */
+  const couponAmount = (): number => {
+    return (Math.trunc(cart.total * 100) - Math.trunc(computePriceWithCoupon(cart.total, cart.coupon) * 100)) / 100.00;
+  };
+
+  /**
+   * Get the paid total amount
+   */
+  const paidTotal = (): number => {
+    return computePriceWithCoupon(cart.total, cart.coupon);
   };
 
   return (
@@ -163,7 +203,7 @@ const StoreCart: React.FC<StoreCartProps> = ({ onSuccess, onError, currentUser,
               </select>
               <div className='total'>
                 <span>{t('app.public.store_cart.total')}</span>
-                <p>{FormatLib.price(item.quantity * item.amount)}</p>
+                <p>{FormatLib.price(itemAmount(item))}</p>
               </div>
               <FabButton className="main-action-btn" onClick={removeProductFromCart(item)}>
                 <i className="fa fa-trash" />
@@ -175,7 +215,7 @@ const StoreCart: React.FC<StoreCartProps> = ({ onSuccess, onError, currentUser,
                   <span>Offer the product</span>
                   <Switch
                   checked={item.is_offered}
-                  onChange={(checked) => onSwitch(item, checked)}
+                  onChange={toogleProductOffer(item)}
                   width={40}
                   height={19}
                   uncheckedIcon={false}
@@ -194,7 +234,7 @@ const StoreCart: React.FC<StoreCartProps> = ({ onSuccess, onError, currentUser,
           <p>[TODO: texte venant des paramètres de la boutique…]</p>
         </div>
 
-        {cart && !cartIsEmpty() && cart.user &&
+        {cart && !cartIsEmpty() &&
           <div className='store-cart-coupon'>
             <CouponInput user={cart.user as User} amount={cart.total} onChange={applyCoupon} />
           </div>
@@ -203,7 +243,7 @@ const StoreCart: React.FC<StoreCartProps> = ({ onSuccess, onError, currentUser,
 
       <aside>
         {cart && !cartIsEmpty() && isPrivileged() &&
-          <div> <MemberSelect onSelected={handleChangeMember} /></div>
+          <div> <MemberSelect onSelected={handleChangeMember} defaultUser={cart.user as User} /></div>
         }
 
         {cart && !cartIsEmpty() && <>
@@ -211,17 +251,17 @@ const StoreCart: React.FC<StoreCartProps> = ({ onSuccess, onError, currentUser,
             <h3>{t('app.public.store_cart.checkout_header')}</h3>
             <span>{t('app.public.store_cart.checkout_products_COUNT', { COUNT: cart?.order_items_attributes.length })}</span>
             <div className="list">
-              <p>{t('app.public.store_cart.checkout_products_total')} <span>{FormatLib.price(cart.total)}</span></p>
-              {offeredAmount() > 0 &&
+              <p>{t('app.public.store_cart.checkout_products_total')} <span>{FormatLib.price(totalBeforeOfferedAmount())}</span></p>
+              {hasOfferedItem() &&
                 <p className='gift'>{t('app.public.store_cart.checkout_gift_total')} <span>-{FormatLib.price(offeredAmount())}</span></p>
               }
-              {cart.coupon && computePriceWithCoupon(cart.total, cart.coupon) !== cart.total &&
-                <p>{t('app.public.store_cart.checkout_coupon')} <span>{FormatLib.price(-(cart.total - computePriceWithCoupon(cart.total, cart.coupon)))}</span></p>
+              {cart.coupon &&
+                <p>{t('app.public.store_cart.checkout_coupon')} <span>-{FormatLib.price(couponAmount())}</span></p>
               }
             </div>
-            <p className='total'>{t('app.public.store_cart.checkout_total')} <span>{FormatLib.price(computePriceWithCoupon(cart.total, cart.coupon))}</span></p>
+            <p className='total'>{t('app.public.store_cart.checkout_total')} <span>{FormatLib.price(paidTotal())}</span></p>
           </div>
-          <FabButton className='checkout-btn' onClick={checkout}>
+          <FabButton className='checkout-btn' onClick={checkout} disabled={!cart.user}>
             {t('app.public.store_cart.checkout')}
           </FabButton>
         </>}
diff --git a/app/frontend/src/javascript/components/coupon/coupon-input.tsx b/app/frontend/src/javascript/components/coupon/coupon-input.tsx
index d3fb917a2..f1cbb8823 100644
--- a/app/frontend/src/javascript/components/coupon/coupon-input.tsx
+++ b/app/frontend/src/javascript/components/coupon/coupon-input.tsx
@@ -1,4 +1,4 @@
-import React, { useState } from 'react';
+import React, { useState, useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import { FabInput } from '../base/fab-input';
 import { FabAlert } from '../base/fab-alert';
@@ -27,6 +27,19 @@ export const CouponInput: React.FC<CouponInputProps> = ({ user, amount, onChange
   const [loading, setLoading] = useState<boolean>(false);
   const [error, setError] = useState<boolean>(false);
   const [coupon, setCoupon] = useState<Coupon>();
+  const [code, setCode] = useState<string>();
+
+  useEffect(() => {
+    if (user && code) {
+      handleChange(code);
+    }
+  }, [user]);
+
+  useEffect(() => {
+    if (code) {
+      handleChange(code);
+    }
+  }, [amount]);
 
   /**
    * callback for validate the code
@@ -36,6 +49,7 @@ export const CouponInput: React.FC<CouponInputProps> = ({ user, amount, onChange
     setMessages([]);
     setError(false);
     setCoupon(null);
+    setCode(value);
     if (value) {
       setLoading(true);
       CouponAPI.validate(value, amount, user?.id).then((res) => {
diff --git a/app/frontend/src/javascript/components/store/store-product-item.tsx b/app/frontend/src/javascript/components/store/store-product-item.tsx
index 7269d8462..4545c22cd 100644
--- a/app/frontend/src/javascript/components/store/store-product-item.tsx
+++ b/app/frontend/src/javascript/components/store/store-product-item.tsx
@@ -12,13 +12,14 @@ import noImage from '../../../../images/no_image.png';
 interface StoreProductItemProps {
   product: Product,
   cart: Order,
-  onSuccessAddProductToCart: (cart: Order) => void
+  onSuccessAddProductToCart: (cart: Order) => void,
+  onError: (message: string) => void
 }
 
 /**
  * This component shows a product item in store
  */
-export const StoreProductItem: React.FC<StoreProductItemProps> = ({ product, cart, onSuccessAddProductToCart }) => {
+export const StoreProductItem: React.FC<StoreProductItemProps> = ({ product, cart, onSuccessAddProductToCart, onError }) => {
   const { t } = useTranslation('public');
 
   /**
@@ -38,7 +39,7 @@ export const StoreProductItem: React.FC<StoreProductItemProps> = ({ product, car
   const addProductToCart = (e: React.BaseSyntheticEvent) => {
     e.preventDefault();
     e.stopPropagation();
-    CartAPI.addItem(cart, product.id, 1).then(onSuccessAddProductToCart);
+    CartAPI.addItem(cart, product.id, 1).then(onSuccessAddProductToCart).catch(onError);
   };
 
   /**
diff --git a/app/frontend/src/javascript/components/store/store-product.tsx b/app/frontend/src/javascript/components/store/store-product.tsx
index 410586ab3..cccca03aa 100644
--- a/app/frontend/src/javascript/components/store/store-product.tsx
+++ b/app/frontend/src/javascript/components/store/store-product.tsx
@@ -7,9 +7,12 @@ import { Loader } from '../base/loader';
 import { IApplication } from '../../models/application';
 import _ from 'lodash';
 import { Product } from '../../models/product';
+import { User } from '../../models/user';
 import ProductAPI from '../../api/product';
+import CartAPI from '../../api/cart';
 import noImage from '../../../../images/no_image.png';
 import { FabButton } from '../base/fab-button';
+import useCart from '../../hooks/use-cart';
 import { FilePdf, Minus, Plus } from 'phosphor-react';
 import { FabStateLabel } from '../base/fab-state-label';
 
@@ -17,15 +20,18 @@ declare const Application: IApplication;
 
 interface StoreProductProps {
   productSlug: string,
+  onSuccess: (message: string) => void,
   onError: (message: string) => void,
+  currentUser?: User
 }
 
 /**
  * This component shows a product
  */
-export const StoreProduct: React.FC<StoreProductProps> = ({ productSlug, onError }) => {
+export const StoreProduct: React.FC<StoreProductProps> = ({ productSlug, currentUser, onSuccess, onError }) => {
   const { t } = useTranslation('public');
 
+  const { cart, setCart } = useCart(currentUser);
   const [product, setProduct] = useState<Product>();
   const [showImage, setShowImage] = useState<number>(null);
   const [toCartCount, setToCartCount] = useState<number>(0);
@@ -37,11 +43,13 @@ export const StoreProduct: React.FC<StoreProductProps> = ({ productSlug, onError
     ProductAPI.get(productSlug).then(data => {
       setProduct(data);
       const productImage = _.find(data.product_images_attributes, { is_main: true });
-      setShowImage(productImage.id);
+      if (productImage) {
+        setShowImage(productImage.id);
+      }
       setToCartCount(data.quantity_min ? data.quantity_min : 1);
       setDisplayToggle(descContainer.current.offsetHeight < descContainer.current.scrollHeight);
-    }).catch(() => {
-      onError(t('app.public.store_product.unexpected_error_occurred'));
+    }).catch((e) => {
+      onError(t('app.public.store_product.unexpected_error_occurred') + e);
     });
   }, []);
 
@@ -108,7 +116,10 @@ export const StoreProduct: React.FC<StoreProductProps> = ({ productSlug, onError
    * Add product to cart
    */
   const addToCart = () => {
-    console.log('Add', toCartCount, 'to cart');
+    CartAPI.addItem(cart, product.id, toCartCount).then(data => {
+      setCart(data);
+      onSuccess(t('app.public.store.add_to_cart_success'));
+    }).catch(onError);
   };
 
   if (product) {
@@ -188,12 +199,12 @@ export const StoreProduct: React.FC<StoreProductProps> = ({ productSlug, onError
   return null;
 };
 
-const StoreProductWrapper: React.FC<StoreProductProps> = ({ productSlug, onError }) => {
+const StoreProductWrapper: React.FC<StoreProductProps> = (props) => {
   return (
     <Loader>
-      <StoreProduct productSlug={productSlug} onError={onError} />
+      <StoreProduct {...props} />
     </Loader>
   );
 };
 
-Application.Components.component('storeProduct', react2angular(StoreProductWrapper, ['productSlug', 'onError']));
+Application.Components.component('storeProduct', react2angular(StoreProductWrapper, ['productSlug', 'currentUser', 'onSuccess', 'onError']));
diff --git a/app/frontend/src/javascript/components/store/store.tsx b/app/frontend/src/javascript/components/store/store.tsx
index a5d140d29..36c7d43ee 100644
--- a/app/frontend/src/javascript/components/store/store.tsx
+++ b/app/frontend/src/javascript/components/store/store.tsx
@@ -11,7 +11,6 @@ import ProductCategoryAPI from '../../api/product-category';
 import MachineAPI from '../../api/machine';
 import { StoreProductItem } from './store-product-item';
 import useCart from '../../hooks/use-cart';
-import { emitCustomEvent } from 'react-custom-events';
 import { User } from '../../models/user';
 import { Order } from '../../models/order';
 import { AccordionItem } from './accordion-item';
@@ -67,10 +66,6 @@ const Store: React.FC<StoreProps> = ({ onError, onSuccess, currentUser }) => {
     });
   }, []);
 
-  useEffect(() => {
-    emitCustomEvent('CartUpdate', cart);
-  }, [cart]);
-
   /**
    * Create categories tree (parent/children)
    */
@@ -234,7 +229,7 @@ const Store: React.FC<StoreProps> = ({ onError, onSuccess, currentUser }) => {
         />
         <div className="products-grid">
           {products.map((product) => (
-            <StoreProductItem key={product.id} product={product} cart={cart} onSuccessAddProductToCart={addToCart} />
+            <StoreProductItem key={product.id} product={product} cart={cart} onSuccessAddProductToCart={addToCart} onError={onError} />
           ))}
         </div>
       </div>
diff --git a/app/frontend/src/javascript/components/user/member-select.tsx b/app/frontend/src/javascript/components/user/member-select.tsx
index 98c7a114c..dfcadf35e 100644
--- a/app/frontend/src/javascript/components/user/member-select.tsx
+++ b/app/frontend/src/javascript/components/user/member-select.tsx
@@ -29,6 +29,12 @@ export const MemberSelect: React.FC<MemberSelectProps> = ({ defaultUser, onSelec
     }
   }, []);
 
+  useEffect(() => {
+    if (!defaultUser && value) {
+      onSelected(value.value);
+    }
+  }, [defaultUser]);
+
   /**
    * search members by name
    */
diff --git a/app/frontend/src/javascript/hooks/use-cart.ts b/app/frontend/src/javascript/hooks/use-cart.ts
index a1617b667..216ea5929 100644
--- a/app/frontend/src/javascript/hooks/use-cart.ts
+++ b/app/frontend/src/javascript/hooks/use-cart.ts
@@ -1,4 +1,5 @@
 import { useState, useEffect } from 'react';
+import { emitCustomEvent } from 'react-custom-events';
 import { Order } from '../models/order';
 import CartAPI from '../api/cart';
 import { getCartToken, setCartToken } from '../lib/cart-token';
@@ -13,7 +14,7 @@ export default function useCart (user?: User) {
     async function createCart () {
       const currentCartToken = getCartToken();
       const data = await CartAPI.create(currentCartToken);
-      setCart(data);
+      _setCart(data);
       setLoading(false);
       setCartToken(data.token);
     }
@@ -30,15 +31,20 @@ export default function useCart (user?: User) {
     setLoading(true);
     const currentCartToken = getCartToken();
     const data = await CartAPI.create(currentCartToken);
-    setCart(data);
+    _setCart(data);
     setLoading(false);
   };
 
   useEffect(() => {
-    if (user && cart && (!cart.statistic_profile_id || !cart.operator_id)) {
+    if (user && cart && (!cart.statistic_profile_id || !cart.operator_profile_id)) {
       reloadCart();
     }
   }, [user]);
 
-  return { loading, cart, error, setCart, reloadCart };
+  const _setCart = (data: Order) => {
+    setCart(data);
+    emitCustomEvent('CartUpdate', data);
+  };
+
+  return { loading, cart, error, setCart: _setCart, reloadCart };
 }
diff --git a/app/frontend/src/javascript/lib/coupon.ts b/app/frontend/src/javascript/lib/coupon.ts
index 7dd8da184..c0eef00e2 100644
--- a/app/frontend/src/javascript/lib/coupon.ts
+++ b/app/frontend/src/javascript/lib/coupon.ts
@@ -5,9 +5,9 @@ export const computePriceWithCoupon = (price: number, coupon?: Coupon): number =
     return price;
   }
   if (coupon.type === 'percent_off') {
-    return price - (price * coupon.percent_off / 100.00);
+    return (Math.trunc(price * 100) - (Math.trunc(price * 100) * coupon.percent_off / 100)) / 100;
   } else if (coupon.type === 'amount_off' && price > coupon.amount_off) {
-    return price - coupon.amount_off;
+    return (Math.trunc(price * 100) - Math.trunc(coupon.amount_off * 100)) / 100;
   }
   return price;
 };
diff --git a/app/frontend/src/javascript/router.js b/app/frontend/src/javascript/router.js
index 8dc6ebf8a..439e15b97 100644
--- a/app/frontend/src/javascript/router.js
+++ b/app/frontend/src/javascript/router.js
@@ -643,8 +643,8 @@ angular.module('application.router', ['ui.router'])
       })
 
       // cart
-      .state('app.public.cart', {
-        url: '/cart',
+      .state('app.public.store_cart', {
+        url: '/store/cart',
         views: {
           'main@': {
             templateUrl: '/cart/index.html',
diff --git a/app/frontend/templates/cart/index.html b/app/frontend/templates/cart/index.html
index ff038fd9d..387395c50 100644
--- a/app/frontend/templates/cart/index.html
+++ b/app/frontend/templates/cart/index.html
@@ -1,6 +1,6 @@
 <div class="header-page">
   <div class="back">
-    <a ng-click="backPrevLocation($event)"><i class="fas fa-long-arrow-alt-left "></i></a>
+    <a ui-sref="app.public.store"><i class="fas fa-long-arrow-alt-left "></i></a>
   </div>
 
   <div class="center">
diff --git a/app/frontend/templates/products/show.html b/app/frontend/templates/products/show.html
index 7123b0a30..54f73efbe 100644
--- a/app/frontend/templates/products/show.html
+++ b/app/frontend/templates/products/show.html
@@ -13,5 +13,5 @@
 </div>
 
 <section class="m-lg">
-  <store-product product-slug="productSlug" on-error="onError" on-success="onSuccess" />
+  <store-product product-slug="productSlug" current-user="currentUser" on-error="onError" on-success="onSuccess" />
 </section>
diff --git a/app/policies/cart_policy.rb b/app/policies/cart_policy.rb
index 4bacdda1e..4772323f4 100644
--- a/app/policies/cart_policy.rb
+++ b/app/policies/cart_policy.rb
@@ -13,4 +13,8 @@ class CartPolicy < ApplicationPolicy
       record.statistic_profile_id.nil? && record.operator_profile_id.nil?
     end
   end
+
+  def set_offer?
+    user.privileged?
+  end
 end
diff --git a/app/services/cart/add_item_service.rb b/app/services/cart/add_item_service.rb
index 298aafbc8..aae1fd32f 100644
--- a/app/services/cart/add_item_service.rb
+++ b/app/services/cart/add_item_service.rb
@@ -15,7 +15,7 @@ class Cart::AddItemService
     else
       item.quantity += quantity.to_i
     end
-    order.total += (orderable.amount * quantity.to_i)
+    order.total += (item.amount * quantity.to_i)
     ActiveRecord::Base.transaction do
       item.save
       order.save
diff --git a/app/services/cart/remove_item_service.rb b/app/services/cart/remove_item_service.rb
index cfa43c1ef..09890a973 100644
--- a/app/services/cart/remove_item_service.rb
+++ b/app/services/cart/remove_item_service.rb
@@ -7,7 +7,7 @@ class Cart::RemoveItemService
 
     raise ActiveRecord::RecordNotFound if item.nil?
 
-    order.total -= (item.amount * item.quantity.to_i)
+    order.total -= (item.amount * item.quantity.to_i) unless item.is_offered
     ActiveRecord::Base.transaction do
       item.destroy!
       order.save
diff --git a/app/services/cart/set_offer_service.rb b/app/services/cart/set_offer_service.rb
new file mode 100644
index 000000000..a5d2ac38f
--- /dev/null
+++ b/app/services/cart/set_offer_service.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+# Provides methods for set offer to item in cart
+class Cart::SetOfferService
+  def call(order, orderable, is_offered)
+    item = order.order_items.find_by(orderable: orderable)
+
+    raise ActiveRecord::RecordNotFound if item.nil?
+
+    if !item.is_offered && is_offered
+      order.total -= (item.amount * item.quantity)
+    elsif item.is_offered && !is_offered
+      order.total += (item.amount * item.quantity)
+    end
+    item.is_offered = is_offered
+    ActiveRecord::Base.transaction do
+      item.save
+      order.save
+    end
+    order.reload
+  end
+end
diff --git a/app/services/cart/set_quantity_service.rb b/app/services/cart/set_quantity_service.rb
index 396716de5..400c622c1 100644
--- a/app/services/cart/set_quantity_service.rb
+++ b/app/services/cart/set_quantity_service.rb
@@ -12,7 +12,7 @@ class Cart::SetQuantityService
     raise ActiveRecord::RecordNotFound if item.nil?
 
     different_quantity = quantity.to_i - item.quantity
-    order.total += (orderable.amount * different_quantity)
+    order.total += (item.amount * different_quantity) unless item.is_offered
     ActiveRecord::Base.transaction do
       item.update(quantity: quantity.to_i)
       order.save
diff --git a/app/services/checkout/payment_service.rb b/app/services/checkout/payment_service.rb
index 6f6e94216..9197de71f 100644
--- a/app/services/checkout/payment_service.rb
+++ b/app/services/checkout/payment_service.rb
@@ -11,7 +11,7 @@ class Checkout::PaymentService
 
     raise Cart::InactiveProductError unless Orders::OrderService.new.all_products_is_active?(order)
 
-    CouponService.new.validate(coupon_code, order.statistic_profile.user)
+    CouponService.new.validate(coupon_code, order.statistic_profile.user.id)
 
     amount = debit_amount(order)
     if operator.privileged? || amount.zero?
diff --git a/app/services/payments/payment_concern.rb b/app/services/payments/payment_concern.rb
index 5e2686ff9..90ea97334 100644
--- a/app/services/payments/payment_concern.rb
+++ b/app/services/payments/payment_concern.rb
@@ -10,7 +10,7 @@ module Payments::PaymentConcern
   end
 
   def debit_amount(order, coupon_code = nil)
-    total = CouponService.new.apply(order.total, coupon_code, order.statistic_profile.user)
+    total = CouponService.new.apply(order.total, coupon_code, order.statistic_profile.user.id)
     wallet_debit = get_wallet_debit(order.statistic_profile.user, total)
     total - wallet_debit
   end
diff --git a/app/views/api/orders/_order.json.jbuilder b/app/views/api/orders/_order.json.jbuilder
index a002b1483..57e1e7808 100644
--- a/app/views/api/orders/_order.json.jbuilder
+++ b/app/views/api/orders/_order.json.jbuilder
@@ -10,7 +10,7 @@ if order&.statistic_profile&.user
   end
 end
 
-json.order_items_attributes order.order_items do |item|
+json.order_items_attributes order.order_items.order(created_at: :asc) do |item|
   json.id item.id
   json.orderable_type item.orderable_type
   json.orderable_id item.orderable_id
diff --git a/config/routes.rb b/config/routes.rb
index 59fe26096..428c5f8e8 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -159,6 +159,7 @@ Rails.application.routes.draw do
       put 'add_item', on: :collection
       put 'remove_item', on: :collection
       put 'set_quantity', on: :collection
+      put 'set_offer', on: :collection
     end
     resources :checkout, only: %i[] do
       post 'payment', on: :collection