diff --git a/app/assets/javascripts/controllers/machines.coffee.erb b/app/assets/javascripts/controllers/machines.coffee.erb
index ff4065d82..76ce33b73 100644
--- a/app/assets/javascripts/controllers/machines.coffee.erb
+++ b/app/assets/javascripts/controllers/machines.coffee.erb
@@ -316,9 +316,6 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
   ## is the user allowed to change the date of his booking
   $scope.enableBookingMove = true
 
-  ## how many hours before the reservation, the user is still allowed to change his booking
-  $scope.moveBookingDelay = 24
-
   ## list of plans, classified by group
   $scope.plansClassifiedByGroup = []
   for group in groupsPromise
@@ -636,15 +633,16 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
 
 
   ##
-  # Format the parameters expected by /api/prices/compute and return the resulting object
+  # Format the parameters expected by /api/prices/compute or /api/reservations and return the resulting object
   # @param reservation {Object} as returned by mkReservation()
   # @param coupon {Object} Coupon as returned from the API
   # @return {{reservation:Object, coupon_id:number}}
   ##
-  mkComputePriceParams = (reservation, coupon) ->
-    params = {reservation: reservation}
-    if coupon
-      params['coupon_id'] = coupon.id
+  mkRequestParams = (reservation, coupon) ->
+    params =
+      reservation: reservation
+      coupon_code: (coupon.code if coupon)
+
     params
 
 
@@ -655,7 +653,7 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
   updateCartPrice = ->
     if Object.keys($scope.ctrl.member).length > 0
       r = mkReservation($scope.ctrl.member, $scope.eventsReserved, $scope.selectedPlan)
-      Price.compute mkComputePriceParams(r, $scope.coupon.applied), (res) ->
+      Price.compute mkRequestParams(r, $scope.coupon.applied), (res) ->
         $scope.amountTotal = res.price
         setSlotsDetails(res.details)
     else
@@ -770,12 +768,15 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
         reservation: ->
           reservation
         price: ->
-          Price.compute(mkComputePriceParams(reservation, $scope.coupon.applied)).$promise
+          Price.compute(mkRequestParams(reservation, $scope.coupon.applied)).$promise
         wallet: ->
           Wallet.getWalletByUser({user_id: reservation.user_id}).$promise
         cgv: ->
           CustomAsset.get({name: 'cgv-file'}).$promise
-      controller: ['$scope', '$uibModalInstance', '$state', 'reservation', 'price', 'cgv', 'Auth', 'Reservation', 'wallet', 'helpers', '$locale', '$filter', ($scope, $uibModalInstance, $state, reservation, price, cgv, Auth, Reservation, wallet, helpers, $locale, $filter) ->
+        coupon: ->
+          $scope.coupon.applied
+      controller: ['$scope', '$uibModalInstance', '$state', 'reservation', 'price', 'cgv', 'Auth', 'Reservation', 'wallet', 'helpers', '$locale', '$filter', 'coupon',
+      ($scope, $uibModalInstance, $state, reservation, price, cgv, Auth, Reservation, wallet, helpers, $locale, $filter, coupon) ->
         # user wallet amount
         $scope.walletAmount = wallet.amount
 
@@ -788,8 +789,10 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
         # Reservation
         $scope.reservation = reservation
 
+        # Currency symbol or abreviation for the current locale
         $scope.currencySymbol = $locale.NUMBER_FORMATS.CURRENCY_SYM
 
+        # Used in wallet info template to interpolate some translations
         $scope.numberFilter = $filter('number')
 
         ##
@@ -801,7 +804,7 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
           else
             $scope.attempting = true
             $scope.reservation.card_token = response.id
-            Reservation.save reservation: $scope.reservation, (reservation) ->
+            Reservation.save mkRequestParams($scope.reservation, coupon), (reservation) ->
               $uibModalInstance.close(reservation)
             , (response)->
               $scope.alerts = []
@@ -827,24 +830,30 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
         reservation: ->
           reservation
         price: ->
-          Price.compute(mkComputePriceParams(reservation, $scope.coupon.applied)).$promise
+          Price.compute(mkRequestParams(reservation, $scope.coupon.applied)).$promise
         wallet: ->
           Wallet.getWalletByUser({user_id: reservation.user_id}).$promise
-      controller: ['$scope', '$uibModalInstance', '$state', 'reservation', 'price', 'Auth', 'Reservation', 'wallet', 'helpers', '$filter', '$locale', ($scope, $uibModalInstance, $state, reservation, price, Auth, Reservation, wallet, helpers, $filter, $locale) ->
+        coupon: ->
+          $scope.coupon.applied
+      controller: ['$scope', '$uibModalInstance', '$state', 'reservation', 'price', 'Auth', 'Reservation', 'wallet', 'helpers', '$filter', '$locale', 'coupon',
+      ($scope, $uibModalInstance, $state, reservation, price, Auth, Reservation, wallet, helpers, $filter, $locale, coupon) ->
+
         # user wallet amount
         $scope.walletAmount = wallet.amount
 
-        # Price
+        # Global price (total of all items)
         $scope.price = price.price
 
-        # price to pay
+        # Price to pay (wallet deducted)
         $scope.amount = helpers.getAmountToPay(price.price, wallet.amount)
 
         # Reservation
         $scope.reservation = reservation
 
+        # Currency symbol or abreviation for the current locale
         $scope.currencySymbol = $locale.NUMBER_FORMATS.CURRENCY_SYM
 
+        # Used in wallet info template to interpolate some translations
         $scope.numberFilter = $filter('number')
 
         # Button label
@@ -861,7 +870,7 @@ Application.Controllers.controller "ReserveMachineController", ["$scope", "$stat
         ##
         $scope.ok = ->
           $scope.attempting = true
-          Reservation.save reservation: $scope.reservation, (reservation) ->
+          Reservation.save mkRequestParams($scope.reservation, coupon), (reservation) ->
             $uibModalInstance.close(reservation)
             $scope.attempting = true
           , (response)->
diff --git a/app/controllers/api/prices_controller.rb b/app/controllers/api/prices_controller.rb
index 66351af97..3974a43c3 100644
--- a/app/controllers/api/prices_controller.rb
+++ b/app/controllers/api/prices_controller.rb
@@ -44,7 +44,7 @@ class API::PricesController < API::ApiController
       @amount = {elements: nil, total: 0}
     else
       _reservable = _price_params[:reservable_type].constantize.find(_price_params[:reservable_id])
-      @amount = Price.compute(current_user.is_admin?, _user, _reservable, _price_params[:slots_attributes], _price_params[:plan_id], _price_params[:nb_reserve_places], _price_params[:nb_reserve_reduced_places], coupon_params[:coupon_id])
+      @amount = Price.compute(current_user.is_admin?, _user, _reservable, _price_params[:slots_attributes], _price_params[:plan_id], _price_params[:nb_reserve_places], _price_params[:nb_reserve_reduced_places], coupon_params[:coupon_code])
     end
 
 
@@ -66,6 +66,6 @@ class API::PricesController < API::ApiController
   end
 
   def coupon_params
-    params.permit(:coupon_id)
+    params.permit(:coupon_code)
   end
 end
diff --git a/app/controllers/api/reservations_controller.rb b/app/controllers/api/reservations_controller.rb
index f7332d0aa..8825b15e5 100644
--- a/app/controllers/api/reservations_controller.rb
+++ b/app/controllers/api/reservations_controller.rb
@@ -22,10 +22,10 @@ class API::ReservationsController < API::ApiController
   def create
     if current_user.is_admin?
       @reservation = Reservation.new(reservation_params)
-      is_reserve = @reservation.save_with_local_payment
+      is_reserve = @reservation.save_with_local_payment(coupon_params[:coupon_code])
     else
       @reservation = Reservation.new(reservation_params.merge(user_id: current_user.id))
-      is_reserve = @reservation.save_with_payment
+      is_reserve = @reservation.save_with_payment(coupon_params[:coupon_code])
     end
     if is_reserve
       SubscriptionExtensionAfterReservation.new(@reservation).extend_subscription_if_eligible
@@ -55,4 +55,8 @@ class API::ReservationsController < API::ApiController
                                         :nb_reserve_places, :nb_reserve_reduced_places,
                                         slots_attributes: [:id, :start_at, :end_at, :availability_id, :offered])
   end
+
+  def coupon_params
+    params.permit(:coupon_code)
+  end
 end
diff --git a/app/models/price.rb b/app/models/price.rb
index 1e74b5005..932225408 100644
--- a/app/models/price.rb
+++ b/app/models/price.rb
@@ -14,10 +14,10 @@ class Price < ActiveRecord::Base
   # @param [plan_id] {Number} if the user is subscribing to a plan at the same time of his reservation, specify the plan's ID here
   # @param [nb_places] {Number} for _reservable_ of type Event, pass here the number of booked places
   # @param [nb_reduced_places] {Number} for _reservable_ of type Event, pass here the number of booked places at reduced price
-  # @param [coupon_id] {Number} ID of the coupon to apply to the total price
+  # @param [coupon_code] {String} Code of the coupon to apply to the total price
   # @return {Hash} total and price detail
   ##
-  def self.compute(admin, user, reservable, slots, plan_id = nil, nb_places = nil, nb_reduced_places = nil, coupon_id = nil)
+  def self.compute(admin, user, reservable, slots, plan_id = nil, nb_places = nil, nb_reduced_places = nil, coupon_code = nil)
     _amount = 0
     _elements = Hash.new
     _elements[:slots] = Array.new
@@ -72,7 +72,7 @@ class Price < ActiveRecord::Base
           training_is_creditable = plan.training_credits.select {|credit| credit.creditable_id == reservable.id}.size > 0
 
           # Training reserved by the user is free when :
-          
+
           # |-> the user already has a current subscription and if training_is_creditable is true and has at least one credit available.
           if !new_plan_being_bought
             if user.training_credits.size < plan.training_credit_nb and training_is_creditable
@@ -112,8 +112,8 @@ class Price < ActiveRecord::Base
     end
 
     # === apply Coupon if any ===
-    unless coupon_id.nil?
-      _coupon = Coupon.find(coupon_id)
+    unless coupon_code.nil?
+      _coupon = Coupon.find_by_code(coupon_code)
       _amount = _amount - (_amount  * _coupon.percent_off / 100)
     end
 
diff --git a/app/models/reservation.rb b/app/models/reservation.rb
index c79cbe4d9..d33bcca7e 100644
--- a/app/models/reservation.rb
+++ b/app/models/reservation.rb
@@ -139,7 +139,7 @@ class Reservation < ActiveRecord::Base
     invoice_items
   end
 
-  def save_with_payment
+  def save_with_payment(coupon_code = nil)
     build_invoice(user: user)
     invoice_items = generate_invoice_items
     if valid?
@@ -259,11 +259,11 @@ class Reservation < ActiveRecord::Base
   end
 
 
-  def save_with_local_payment
+  def save_with_local_payment(coupon_code = nil)
     if user.invoicing_disabled?
       if valid?
 
-        ### generate invoice only for calcul price, to refactoring!!
+        ### generate invoice only for calcul price, TODO refactor!!
         build_invoice(user: user)
         generate_invoice_items(true)
         @wallet_amount_debit = get_wallet_amount_debit
@@ -353,13 +353,14 @@ class Reservation < ActiveRecord::Base
   end
 
   def get_wallet_amount_debit
-    total = self.invoice.invoice_items.map(&:amount).map(&:to_i).reduce(:+) or 0
+    total = (self.invoice.invoice_items.map(&:amount).map(&:to_i).reduce(:+) or 0)
     if plan_id.present?
       plan = Plan.find(plan_id)
       total += plan.amount
     end
     wallet_amount = (user.wallet.amount * 100).to_i
-    return wallet_amount >= total ? total : wallet_amount
+
+    wallet_amount >= total ? total : wallet_amount
   end
 
   def debit_user_wallet