diff --git a/.fabmanager-version b/.fabmanager-version
index 62e64205b..48a6b508d 100644
--- a/.fabmanager-version
+++ b/.fabmanager-version
@@ -1 +1 @@
-2.4.6
\ No newline at end of file
+2.4.7
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index ee0e0fc32..9a35a3571 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,6 +15,7 @@
 # Ignore all logfiles and tempfiles.
 /log/*.log
 /tmp
+/coverage
 
 /public/uploads
 /public/assets
@@ -39,5 +40,8 @@
 .vagrant
 .docker
 
+# Do not versionate coveralls token
+.coveralls.yml
+
 # Plugins are versioned is their own repository
 /plugins/*
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ed68f9cc0..e2922cf17 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,18 @@
 # Changelog Fab Manager
 
-## v2.4.6 2016 Novembre 30
+## v2.4.7 2016 December 14
+
+- Improved automated testing
+- Added an information notice about the processing time of deleting an administrator
+- Ability to change the expiration date of a coupon after its creation
+- Ability to generate a refund invoice when crediting user's wallet
+- Fix a bug: unable to run rake db:migrate on first install
+- Fix a bug: unable to create or edit a coupon of type 'percentage'
+
+## v2.4.6 2016 November 30
 
 - Change display of message about coupon application status
-- Fix a bug: compute price API return error 500 if reservable_id is not provided 
+- Fix a bug: compute price API return error 500 if reservable_id is not provided
 
 ## v2.4.5 2016 November 29
 
@@ -25,8 +34,8 @@
 ## v2.4.3 2016 November 21
 
 - Export user's invoicing status in members' excel export
-- Fix a bug: Next events descriptions, shown on the home page, display raw html 
-- Fix a bug: number of reserved seats for an event is always of 1 in the excel export of reservations 
+- Fix a bug: Next events descriptions, shown on the home page, display raw html
+- Fix a bug: number of reserved seats for an event is always of 1 in the excel export of reservations
 - Fix a bug: conflict between similar translations around "reservations"
 - Fix a bug: later occurrences of recurrent events does not have the initially configured theme and age range
 - Fix a bug: some graphs do not display: events, users, trainings and machine hours
@@ -44,18 +53,18 @@
 
 ## v2.4.1 2016 October 11
 
-- Fix a bug: unable to share a project/event without image on social networks 
+- Fix a bug: unable to share a project/event without image on social networks
 - Fix a bug: after creating an element in the admin calendar, browsing through the calendar and coming back cause the element to appear duplicated
 - Fix a bug: after deleting an element in the admin calendar, the confirmation message is wrong and an error is logged in the console
 - Fix a bug: erroneous syntax in docker env example file
 
 ## v2.4.0 2016 October 4
- 
+
 - RSS feeds to follow new projects and events published
 - Use slugs in projects URL opened from notifications
 - Ask for confirmation on machine deletion from the public view
 - Ability to delete a training from the public view for an admin
-- Project images will show in full-size on a click 
+- Project images will show in full-size on a click
 - Add a checkbox "I accept to receive informations from the FabLab" on Sign-up dialog and user's profile
 - Share project with Facebook/Twitter
 - Display fab-manager's version in "Powered by" label, when logged as admin
@@ -70,14 +79,14 @@
 - Trainings are associated with a picture and an HTML textual description
 - Public gallery of trainings with ability to view details or to book a training on its own calendar
 - Ability to switch back to all trainings booking view
-- Rename "Courses and Workshops" to "Events" 
+- Rename "Courses and Workshops" to "Events"
 - Admin: Events can be associated with a theme and an age range
 - Admin: Event categories, themes and age ranges can be customized
 - Filter events by category, theme and age range in public view
 - Ability to customise price's categories for the events
 - Events can be associated with many custom price's categories, instead of only one "reduced price"
 - Statistics views can trigger and display custom aggregations from ElasticSearch
-- Machine hours/Trainings statistics: display number of tickets/hours available for booking 
+- Machine hours/Trainings statistics: display number of tickets/hours available for booking
 - Statistics will include informations abouts events category, theme and age range
 - Ability to export the current statistics table to an Excel file
 - Ability to export every statistics on a given dates range to an Excel file
@@ -93,16 +102,16 @@
 - More file types allowed as project CAD attachements
 - Project CAD attachements are now checked by MIME type in addition of extension check
 - Project CAD attachement allowed are now configured in environment variables
-- Project CAD attachement extensions allowed are shown next to input field 
+- Project CAD attachement extensions allowed are shown next to input field
 - Display strategy's name in SSO providers list
 - SSO: documentation improved with an usage example
 - SSO: mapped fields display their data type. Integers, booleans and dates allow some transformations.
 - Fix a bug: project drafts are shown on public profiles
 - Fix a bug: event category disappear when editing the event
-- Fix a bug: machine name is not shown in plan edition 
+- Fix a bug: machine name is not shown in plan edition
 - Fix a bug: machine slots with tags are not displayed correctly on reservation calendar
 - Fix a bug: avatar, address and organization details mapping from SSO were broken
-- Fix a bug: in SSO configuration some valid endpoints were recognized as erroneous 
+- Fix a bug: in SSO configuration some valid endpoints were recognized as erroneous
 - Fix a bug: clicking on the text in stripe's payment modal, does not validate the checkbox
 - Fix a bug: move event reservation is not limited by admin settings (prior-delay & disable)
 - Fix a bug: UI issues on small devices (dashboard + admin views)
@@ -134,7 +143,7 @@
 - [TODO DEPLOY] `bundle install` and `rake db:migrate`
 
 ## v2.2.2 2016 June 23
-- Fix some bugs: users with uncompleted account (sso imported) won't appear in statistics, in listings and in searches. Moreover, they won't block statistics generation 
+- Fix some bugs: users with uncompleted account (sso imported) won't appear in statistics, in listings and in searches. Moreover, they won't block statistics generation
 - Fix a bug: unable to display next results in statistics tables
 - Admin: Category is mandatory when creating an event
 
@@ -150,7 +159,7 @@
 - User public profile: UI re-design with possible admin's customization
 - Admin: Invoices list and users list are now loaded per 10 items to improve pages load time
 - Admin: select member (eg. to buy a subscription for a member) is now loading the user's list dynamically when you type
-- Project collaborators selection is now using a list dynamically loaded as you type 
+- Project collaborators selection is now using a list dynamically loaded as you type
 - Admin: select a training before monitoring its reservations -> improves page load time
 - API: GET /api/trainings do not load nor send the associated availabilities until they are requested
 - List of members is now loaded 10 members by 10, to improve page load time
diff --git a/Gemfile b/Gemfile
index b0250b9a7..a2394f4fc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -52,6 +52,8 @@ group :development do
   gem 'capistrano-maintenance', '0.0.5', require: false
 
   gem 'active_record_query_trace'
+
+  gem 'coveralls', require: false
 end
 
 group :test do
@@ -62,6 +64,7 @@ group :test do
   gem 'webmock'
   gem 'vcr'
   gem 'byebug'
+  gem 'pdf-reader'
 end
 
 group :production do
diff --git a/Gemfile.lock b/Gemfile.lock
index 6e602afad..0eab18efc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,6 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    Ascii85 (1.0.2)
     aasm (4.1.0)
     actionmailer (4.2.5)
       actionpack (= 4.2.5)
@@ -41,6 +42,7 @@ GEM
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
     addressable (2.3.8)
+    afm (0.2.2)
     ansi (1.5.0)
     api-pagination (4.3.0)
     apipie-rails (0.3.6)
@@ -118,6 +120,12 @@ GEM
       sass-rails (<= 5.0.1)
       sprockets (< 2.13)
     connection_pool (2.2.0)
+    coveralls (0.8.16)
+      json (>= 1.8, < 3)
+      simplecov (~> 0.12.0)
+      term-ansicolor (~> 1.3.0)
+      thor (~> 0.19.1)
+      tins (>= 1.6.0, < 2)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
     database_cleaner (1.4.1)
@@ -133,6 +141,7 @@ GEM
       warden (~> 1.2.3)
     devise-async (0.9.0)
       devise (~> 3.2)
+    docile (1.1.5)
     domain_name (0.5.25)
       unf (>= 0.0.5, < 1.0.0)
     elasticsearch (1.0.12)
@@ -177,6 +186,7 @@ GEM
     has_secure_token (1.0.0)
       activerecord (>= 3.0)
     hashdiff (0.3.0)
+    hashery (2.1.2)
     hashie (3.4.2)
     highline (1.7.1)
     hike (1.2.3)
@@ -265,6 +275,12 @@ GEM
       httparty (~> 0.13)
     orm_adapter (0.5.0)
     pdf-core (0.5.1)
+    pdf-reader (1.4.0)
+      Ascii85 (~> 1.0.0)
+      afm (~> 0.2.1)
+      hashery (~> 2.0)
+      ruby-rc4
+      ttfunk
     pg (0.18.1)
     pkg-config (1.1.7)
     prawn (2.0.1)
@@ -335,6 +351,7 @@ GEM
       netrc (~> 0.7)
     rolify (4.0.0)
     ruby-progressbar (1.7.5)
+    ruby-rc4 (0.1.5)
     rubyzip (1.1.7)
     rufus-scheduler (3.0.9)
       tzinfo
@@ -365,6 +382,11 @@ GEM
       sidekiq (>= 2.17.3)
       tilt (< 2.0.0)
     simple_oauth (0.3.1)
+    simplecov (0.12.0)
+      docile (~> 1.1.0)
+      json (>= 1.8, < 3)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.0)
     sinatra (1.4.6)
       rack (~> 1.4)
       rack-protection (~> 1.4)
@@ -382,6 +404,8 @@ GEM
     stripe (1.30.2)
       json (~> 1.8.1)
       rest-client (~> 1.4)
+    term-ansicolor (1.3.2)
+      tins (~> 1.0)
     test_after_commit (1.0.0)
       activerecord (>= 3.2)
     therubyracer (0.12.0)
@@ -392,6 +416,7 @@ GEM
     tilt (1.4.1)
     timers (4.0.1)
       hitimes
+    tins (1.13.0)
     ttfunk (1.4.0)
     twitter (5.14.0)
       addressable (~> 2.3)
@@ -462,6 +487,7 @@ DEPENDENCIES
   chroma
   coffee-rails (~> 4.1.0)
   compass-rails (= 2.0.4)
+  coveralls
   database_cleaner
   devise
   devise-async
@@ -488,6 +514,7 @@ DEPENDENCIES
   omniauth
   omniauth-oauth2
   openlab_ruby
+  pdf-reader
   pg
   prawn
   prawn-table
@@ -522,4 +549,4 @@ DEPENDENCIES
   webmock
 
 BUNDLED WITH
-   1.12.5
+   1.13.1
diff --git a/app/assets/javascripts/controllers/admin/coupons.coffee b/app/assets/javascripts/controllers/admin/coupons.coffee
index 21e0a65ae..c62693e80 100644
--- a/app/assets/javascripts/controllers/admin/coupons.coffee
+++ b/app/assets/javascripts/controllers/admin/coupons.coffee
@@ -58,8 +58,8 @@ Application.Controllers.controller "NewCouponController", ["$scope", "$state", '
 ##
 # Controller used in the coupon edition page
 ##
-Application.Controllers.controller "EditCouponController", ["$scope", "$state",  'Coupon', 'couponPromise', '_t'
-, ($scope, $state, Coupon, couponPromise, _t) ->
+Application.Controllers.controller "EditCouponController", ["$scope", "$state",  'Coupon', 'couponPromise', '_t', 'growl'
+, ($scope, $state, Coupon, couponPromise, _t, growl) ->
 
   ### PUBLIC SCOPE ###
 
@@ -73,6 +73,9 @@ Application.Controllers.controller "EditCouponController", ["$scope", "$state",
   ## Options for the validity per user
   $scope.validities = userValidities
 
+  ## Mapping for validation errors
+  $scope.errors = {}
+
   ## Default parameters for AngularUI-Bootstrap datepicker (used for coupon validity limit selection)
   $scope.datePicker =
     format: Fablab.uibDateFormat
@@ -98,11 +101,12 @@ Application.Controllers.controller "EditCouponController", ["$scope", "$state",
   # Callback to save the coupon's changes to the API
   ##
   $scope.updateCoupon = ->
+    $scope.errors = {}
     Coupon.update {id: $scope.coupon.id}, coupon: $scope.coupon, (coupon) ->
       $state.go('app.admin.pricing')
     , (err)->
       growl.error(_t('unable_to_update_the_coupon_an_error_occurred'))
-      console.error(err)
+      $scope.errors = err.data
 
 
 
diff --git a/app/assets/javascripts/controllers/admin/members.coffee.erb b/app/assets/javascripts/controllers/admin/members.coffee.erb
index 9c37206d8..14b2c42a9 100644
--- a/app/assets/javascripts/controllers/admin/members.coffee.erb
+++ b/app/assets/javascripts/controllers/admin/members.coffee.erb
@@ -105,8 +105,8 @@ class MembersController
 ##
 # Controller used in the members/groups management page
 ##
-Application.Controllers.controller "AdminMembersController", ["$scope", 'membersPromise', 'adminsPromise', 'growl', 'Admin', 'dialogs', '_t', 'Member', 'Export'
-, ($scope, membersPromise, adminsPromise, growl, Admin, dialogs, _t, Member, Export) ->
+Application.Controllers.controller "AdminMembersController", ["$scope","$sce", 'membersPromise', 'adminsPromise', 'growl', 'Admin', 'dialogs', '_t', 'Member', 'Export'
+, ($scope, $sce, membersPromise, adminsPromise, growl, Admin, dialogs, _t, Member, Export) ->
 
 
 
@@ -177,7 +177,7 @@ Application.Controllers.controller "AdminMembersController", ["$scope", 'members
       resolve:
         object: ->
           title: _t('confirmation_required')
-          msg: _t('do_you_really_want_to_delete_this_administrator_this_cannot_be_undone')
+          msg: $sce.trustAsHtml(_t('do_you_really_want_to_delete_this_administrator_this_cannot_be_undone') + '<br/><br/>' +_t('this_may_take_a_while_please_wait'))
     , -> # cancel confirmed
       Admin.delete id: admin.id, ->
         admins.splice(findAdminIdxById(admins, admin.id), 1)
@@ -423,11 +423,40 @@ Application.Controllers.controller "EditMemberController", ["$scope", "$state",
       templateUrl: '<%= asset_path "wallet/credit_modal.html" %>'
       controller: ['$scope', '$uibModalInstance', 'Wallet', ($scope, $uibModalInstance, Wallet) ->
 
+        # default: do not generate a refund invoice
+        $scope.generate_avoir = false
+
+        # date of the generated refund invoice
+        $scope.avoir_date = null
+
+        # optional description shown on the refund invoice
+        $scope.description = ''
+
+        # default configuration for the avoir date selector widget
+        $scope.datePicker =
+          format: Fablab.uibDateFormat
+          opened: false
+          options:
+            startingDay: Fablab.weekStartingDay
+
+        ##
+        # Callback to open/close the date picker
+        ##
+        $scope.toggleDatePicker = ($event) ->
+          $event.preventDefault()
+          $event.stopPropagation()
+          $scope.datePicker.opened = !$scope.datePicker.opened
+
         ##
         # Modal dialog validation callback
         ##
         $scope.ok = ->
-          Wallet.credit { id: wallet.id }, { amount: $scope.amount }, (_wallet)->
+          Wallet.credit { id: wallet.id },
+            amount: $scope.amount
+            avoir: $scope.generate_avoir
+            avoir_date: $scope.avoir_date
+            avoir_description: $scope.description
+          , (_wallet)->
 
             growl.success(_t('wallet_credit_successfully'))
             $uibModalInstance.close(_wallet)
diff --git a/app/assets/templates/admin/coupons/_form.html.erb b/app/assets/templates/admin/coupons/_form.html.erb
index 4cc92c9f6..9a54b7995 100644
--- a/app/assets/templates/admin/coupons/_form.html.erb
+++ b/app/assets/templates/admin/coupons/_form.html.erb
@@ -81,7 +81,7 @@
   <span class="help-block error" ng-show="couponForm['coupon[validity_per_user]'].$dirty && couponForm['coupon[validity_per_user]'].$error.required" translate>{{ 'validity_per_user_is_required' }}</span>
 </div>
 
-<div class="form-group">
+<div class="form-group" ng-class="{'has-error': errors['valid_until']}">
   <label for="coupon[valid_until]" translate>{{ 'valid_until' }}</label>
   <div class="input-group">
     <input type="text" id="coupon[valid_until]"
@@ -92,16 +92,16 @@
            datepicker-options="datePicker.options"
            is-open="datePicker.opened"
            min-date="datePicker.minDate"
-           ng-disabled="mode == 'EDIT'"
            ng-click="toggleDatePicker($event)"/>
     <span class="input-group-btn">
       <button type="button" class="btn btn-default" ng-click="toggleDatePicker($event)" ng-disabled="mode == 'EDIT'"><i class="fa fa-calendar"></i></button>
     </span>
   </div>
+  <span class="help-block error" ng-show="errors['valid_until']">{{ errors['valid_until'].join(' ; ') }}</span>
 
-  <span class="help-block text-info text-xs">
-      <i class="fa fa-lightbulb-o"></i> {{ 'leave_empty_for_no_limit' | translate }}
-    </span>
+  <span class="text-info text-xs">
+    <i class="fa fa-lightbulb-o"></i> {{ 'leave_empty_for_no_limit' | translate }}
+  </span>
 </div>
 
 <div class="form-group" ng-class="{'has-error': couponForm['coupon[max_usages]'].$dirty && couponForm['coupon[max_usages]'].$invalid}">
@@ -114,7 +114,7 @@
          min="0"/>
   <span class="help-block error" ng-show="couponForm['coupon[max_usages]'].$dirty && couponForm['coupon[max_usages]'].$error.min" translate>{{ 'max_usages_must_be_equal_or_greater_than_0' }}</span>
 
-  <span class="help-block text-info text-xs">
+  <span class="text-info text-xs">
     <i class="fa fa-lightbulb-o"></i> {{ 'leave_empty_for_no_limit' | translate }}
   </span>
 </div>
diff --git a/app/assets/templates/shared/confirm_modal.html.erb b/app/assets/templates/shared/confirm_modal.html.erb
index 250bb78c1..b32db0943 100644
--- a/app/assets/templates/shared/confirm_modal.html.erb
+++ b/app/assets/templates/shared/confirm_modal.html.erb
@@ -3,7 +3,7 @@
   <h1>{{object.title}}</h1>
 </div>
 <div class="modal-body">
-  <p>{{object.msg}}</p>
+  <p ng-bind-html="object.msg"></p>
 </div>
 <div class="modal-footer">
   <button class="btn btn-info" ng-click="ok()" translate>{{ 'confirm' }}</button>
diff --git a/app/assets/templates/wallet/credit_modal.html.erb b/app/assets/templates/wallet/credit_modal.html.erb
index 7624e12a9..80e0baf54 100644
--- a/app/assets/templates/wallet/credit_modal.html.erb
+++ b/app/assets/templates/wallet/credit_modal.html.erb
@@ -3,11 +3,18 @@
   <h1 translate>{{ 'credit_title' }}</h1>
 </div>
 <div class="modal-body">
+
+  <div class="alert alert-warning m-b-md m-b-sm">
+    <i class="fa fa-warning m-sm inline" aria-hidden="true"></i>
+    <div class="inline pull-right width-90 m-t-n-xs" translate>{{ 'warning_uneditable_credit' }}</div>
+  </div>
+
   <form name="walletForm" ng-class="{'has-error': walletForm.amount.$dirty && walletForm.amount.$invalid}">
     <div class="text-right amountGroup m-r-md">
-      <span class="beforeAmount" translate>{{ 'credit_label' }}</span>
+      <label for="amount" class="beforeAmount" translate>{{ 'credit_label' }}</label>
       <input class="form-control m-l"
              type="number"
+             id="amount"
              name="amount"
              ng-model="amount"
              required min="1"
@@ -16,10 +23,11 @@
       <span class="help-block" ng-show="walletForm.amount.$dirty && walletForm.amount.$error.required" translate>{{'amount_is_required'}}</span>
       <span class="help-block" ng-show="walletForm.amount.$dirty && walletForm.amount.$error.min">{{ 'amount_minimum_1' | translate }} {{currencySymbol}}.</span>
     </div>
-    <div class="text-right amountGroup m-t m-r-md">
-      <span class="beforeAmount" translate>{{ 'confirm_credit_label' }}</span>
+    <div class="text-right amountGroup m-t m-r-md" ng-class="{'has-error': walletForm.amount_confirm.$dirty && walletForm.amount_confirm.$invalid }">
+      <label for="amount_confirm" class="beforeAmount" translate>{{ 'confirm_credit_label' }}</label>
       <input class="form-control m-l"
              type="number"
+             id="amount_confirm"
              name="amount_confirm"
              ng-model="amount_confirm"
              required
@@ -30,12 +38,53 @@
       <span class="help-block" ng-show="walletForm.amount_confirm.$dirty && walletForm.amount_confirm.$error.required" translate>{{'amount_confirm_is_required'}}</span>
       <span class="help-block" ng-show="walletForm.amount_confirm.$dirty && walletForm.amount_confirm.$error.pattern">{{ 'amount_confirm_does_not_match' | translate }}</span>
     </div>
-  </form>
 
-  <div class="alert alert-warning m-t-md m-b-sm">
-    <i class="fa fa-warning m-sm inline" aria-hidden="true"></i>
-    <div class="inline pull-right width-90 m-t-n-xs" translate>{{ 'warning_uneditable_credit' }}</div>
-  </div>
+    <hr/>
+    <div class="text-right m-t">
+      <label for="generate_avoir" translate>{{ 'generate_a_refund_invoice' }}</label>
+      <div class="inline m-l">
+        <input bs-switch
+               ng-model="generate_avoir"
+               id="generate_avoir"
+               name="generate_avoir"
+               type="checkbox"
+               switch-on-text="{{ 'yes' | translate }}"
+               switch-off-text="{{ 'no' | translate }}"
+               switch-animate="true"/>
+      </div>
+    </div>
+
+    <div ng-show="generate_avoir">
+      <div class="m-t" ng-class="{'has-error': walletForm.avoir_date.$dirty && walletForm.avoir_date.$invalid }">
+        <label  for="avoir_date" translate>{{ 'creation_date_for_the_refund' }}</label>
+          <div class="input-group">
+            <span class="input-group-addon"><i class="fa fa-calendar"></i></span>
+            <input type="text"
+                   class="form-control"
+                   id="avoir_date"
+                   name="avoir_date"
+                   ng-model="avoir_date"
+                   uib-datepicker-popup="{{datePicker.format}}"
+                   datepicker-options="datePicker.options"
+                   is-open="datePicker.opened"
+                   placeholder="{{datePicker.format}}"
+                   ng-click="toggleDatePicker($event)"
+                   ng-required="generate_avoir"/>
+          </div>
+        <span class="help-block" ng-show="walletForm.avoir_date.$dirty && walletForm.avoir_date.$error.required" translate>{{ 'creation_date_is_required' }}</span>
+      </div>
+
+      <div class="m-t">
+        <label for="description" translate>{{ 'description_(optional)' }}</label>
+        <p translate>{{ 'will_appear_on_the_refund_invoice' }}</p>
+        <textarea class="form-control m-t-sm"
+                  id="description"
+                  name="description"
+                  ng-model="description">
+        </textarea>
+      </div>
+    </div>
+  </form>
 
 </div>
 <div class="modal-footer">
diff --git a/app/controllers/api/coupons_controller.rb b/app/controllers/api/coupons_controller.rb
index 9057a2123..d214f1961 100644
--- a/app/controllers/api/coupons_controller.rb
+++ b/app/controllers/api/coupons_controller.rb
@@ -90,6 +90,6 @@ class API::CouponsController < API::ApiController
   end
 
   def coupon_editable_params
-    params.require(:coupon).permit(:name, :active)
+    params.require(:coupon).permit(:name, :active, :valid_until)
   end
 end
diff --git a/app/controllers/api/invoices_controller.rb b/app/controllers/api/invoices_controller.rb
index 22f210a68..2a0712d2e 100644
--- a/app/controllers/api/invoices_controller.rb
+++ b/app/controllers/api/invoices_controller.rb
@@ -57,7 +57,7 @@ class API::InvoicesController < API::ApiController
 
   end
 
-  # only for create avoir
+  # only for create refund invoices (avoir)
   def create
     authorize Invoice
     invoice = Invoice.only_invoice.find(avoir_params[:invoice_id])
diff --git a/app/controllers/api/wallet_controller.rb b/app/controllers/api/wallet_controller.rb
index 5ff142155..58f301c1f 100644
--- a/app/controllers/api/wallet_controller.rb
+++ b/app/controllers/api/wallet_controller.rb
@@ -14,13 +14,22 @@ class API::WalletController < API::ApiController
   end
 
   def credit
-    @wallet = Wallet.find(params[:id])
+    @wallet = Wallet.find(credit_params[:id])
     authorize @wallet
     service = WalletService.new(user: current_user, wallet: @wallet)
-    if service.credit(params[:amount].to_f)
+    transaction = service.credit(credit_params[:amount].to_f)
+    if transaction
+      if credit_params[:avoir]
+        service.create_avoir(transaction, credit_params[:avoir_date], credit_params[:avoir_description])
+      end
       render :show
     else
       head 422
     end
   end
+
+  private
+  def credit_params
+    params.permit(:id, :amount, :avoir, :avoir_date, :avoir_description)
+  end
 end
diff --git a/app/models/coupon.rb b/app/models/coupon.rb
index b4fe0a7f8..69b37310e 100644
--- a/app/models/coupon.rb
+++ b/app/models/coupon.rb
@@ -11,6 +11,7 @@ class Coupon < ActiveRecord::Base
   validates :validity_per_user, presence: true
   validates :validity_per_user, inclusion: { in: %w(once forever) }
   validates_with CouponDiscountValidator
+  validates_with CouponExpirationValidator
 
   def safe_destroy
     if self.invoices.size == 0
@@ -76,6 +77,7 @@ class Coupon < ActiveRecord::Base
                             attached_object: self
   end
 
+  private
   def create_stripe_coupon
     StripeWorker.perform_async(:create_stripe_coupon, id)
   end
diff --git a/app/pdfs/pdf/invoice.rb b/app/pdfs/pdf/invoice.rb
index ab9b8b20e..faf79f42d 100644
--- a/app/pdfs/pdf/invoice.rb
+++ b/app/pdfs/pdf/invoice.rb
@@ -37,10 +37,12 @@ module PDF
         if Setting.find_by({name: 'invoice_code-active'}).value == 'true'
           text I18n.t('invoices.code', CODE:Setting.find_by({name: 'invoice_code-value'}).value), :leading => 3
         end
-        if invoice.is_a?(Avoir)
-          text I18n.t('invoices.order_number', NUMBER:invoice.invoice.order_number), :leading => 3
-        else
-          text I18n.t('invoices.order_number', NUMBER:invoice.order_number), :leading => 3
+        if invoice.invoiced_type != WalletTransaction.name
+          if invoice.is_a?(Avoir)
+            text I18n.t('invoices.order_number', NUMBER:invoice.invoice.order_number), :leading => 3
+          else
+            text I18n.t('invoices.order_number', NUMBER:invoice.order_number), :leading => 3
+          end
         end
         if invoice.is_a?(Avoir)
           text I18n.t('invoices.refund_invoice_issued_on_DATE', DATE:I18n.l(invoice.avoir_date.to_date))
@@ -68,7 +70,11 @@ module PDF
         # object
         move_down 25
         if invoice.is_a?(Avoir)
-          object = I18n.t('invoices.cancellation_of_invoice_REF', REF: invoice.invoice.reference)
+          if invoice.invoiced_type == WalletTransaction.name
+            object = I18n.t('invoices.wallet_credit')
+          else
+            object = I18n.t('invoices.cancellation_of_invoice_REF', REF: invoice.invoice.reference)
+          end
         else
           case invoice.invoiced_type
             when 'Reservation'
@@ -115,7 +121,7 @@ module PDF
 
 
           else ### Reservation
-            case invoice.invoiced.reservable_type
+            case invoice.invoiced.try(:reservable_type)
               ### Machine reservation
               when 'Machine'
                 details += I18n.t('invoices.machine_reservation_DESCRIPTION', DESCRIPTION: item.description)
@@ -130,6 +136,9 @@ module PDF
                 invoice.invoiced.tickets.each do |t|
                   details += "\n  "+I18n.t('invoices.other_rate_ticket', count: t.booked, NAME: t.event_price_category.price_category.name)
                 end
+              ### wallet credit
+              when nil
+                details = item.description
 
               ### Other cases (not expected)
               else
diff --git a/app/services/wallet_service.rb b/app/services/wallet_service.rb
index 23a824529..c8ebea8be 100644
--- a/app/services/wallet_service.rb
+++ b/app/services/wallet_service.rb
@@ -21,7 +21,7 @@ class WalletService
       end
       raise ActiveRecord::Rollback
     end
-    return false
+    false
   end
 
   ## debit an amount to wallet, if debit success then return a wallet transaction
@@ -35,6 +35,27 @@ class WalletService
       end
       raise ActiveRecord::Rollback
     end
-    return false
+    false
+  end
+
+  ## create a refund invoice associated with the given wallet transaction
+  def create_avoir(wallet_transaction, avoir_date, description)
+    avoir = Avoir.new
+    avoir.type = 'Avoir'
+    avoir.invoiced = wallet_transaction
+    avoir.avoir_date = avoir_date
+    avoir.created_at = avoir_date
+    avoir.description = description
+    avoir.avoir_mode = 'wallet'
+    avoir.subscription_to_expire = false
+    avoir.user_id = wallet_transaction.wallet.user_id
+    avoir.total = wallet_transaction.amount * 100.0
+    avoir.save!
+
+    ii = InvoiceItem.new
+    ii.amount = wallet_transaction.amount * 100.0
+    ii.description = I18n.t('invoices.wallet_credit')
+    ii.invoice = avoir
+    ii.save!
   end
 end
diff --git a/app/validators/coupon_discount_validator.rb b/app/validators/coupon_discount_validator.rb
index 35b81b0f6..60a674804 100644
--- a/app/validators/coupon_discount_validator.rb
+++ b/app/validators/coupon_discount_validator.rb
@@ -1,15 +1,15 @@
 class CouponDiscountValidator < ActiveModel::Validator
   def validate(record)
     if !record.percent_off.nil?
-      unless [0..100].include? record.percent_off
-        record.errors[:percent_off] << 'Percentage must be included between 0 and 100'
+      unless (0..100).include? record.percent_off
+        record.errors[:percent_off] << I18n.t('errors.messages.percentage_out_of_range')
       end
     elsif !record.amount_off.nil?
       unless record.amount_off > 0
         record.errors[:amount_off] << I18n.t('errors.messages.greater_than_or_equal_to', count: 0)
       end
     else
-      record.errors[:percent_off] << 'cannot be blank when amount_off is blank too'
+      record.errors[:percent_off] << I18n.t('errors.messages.cannot_be_blank_at_same_time', field: 'amount_off')
     end
   end
 end
\ No newline at end of file
diff --git a/app/validators/coupon_expiration_validator.rb b/app/validators/coupon_expiration_validator.rb
new file mode 100644
index 000000000..d9a80f55e
--- /dev/null
+++ b/app/validators/coupon_expiration_validator.rb
@@ -0,0 +1,19 @@
+class CouponExpirationValidator < ActiveModel::Validator
+  ##
+  # @param record {Coupon}
+  ##
+  def validate(record)
+    previous = record.valid_until_was
+    current = record.valid_until
+
+    unless current.blank?
+      if current.end_of_day < Time.now
+        record.errors[:valid_until] << I18n.t('errors.messages.cannot_be_in_the_past')
+      end
+
+      if !previous.blank? and current.end_of_day < previous.end_of_day
+        record.errors[:valid_until] << I18n.t('errors.messages.cannot_be_before_previous_value')
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/config/initializers/elasticsearch.rb b/config/initializers/elasticsearch.rb
index 5f8f7d446..1e6b9966e 100644
--- a/config/initializers/elasticsearch.rb
+++ b/config/initializers/elasticsearch.rb
@@ -1,3 +1,8 @@
-client = Elasticsearch::Client.new host: "http://#{Rails.application.secrets.elaticsearch_host}:9200", log: true
+if Rails.env.test?
+  client = Elasticsearch::Client.new host: "http://#{Rails.application.secrets.elaticsearch_host}:9200", log: false
+else
+  client = Elasticsearch::Client.new host: "http://#{Rails.application.secrets.elaticsearch_host}:9200", log: true
+end
+
 Elasticsearch::Model.client = client
 Elasticsearch::Persistence.client = client
diff --git a/config/locales/app.admin.en.yml b/config/locales/app.admin.en.yml
index bb0d52ad7..53237b8c3 100644
--- a/config/locales/app.admin.en.yml
+++ b/config/locales/app.admin.en.yml
@@ -336,6 +336,7 @@ en:
         groups: "Groups"
         authentication: "Authentication"
         do_you_really_want_to_delete_this_administrator_this_cannot_be_undone: "Do you really want to delete this administrator? This cannot be undone."
+        this_may_take_a_while_please_wait: "Warning: this may take a while, please be patient."
         administrator_successfully_deleted: "Administrator successfully deleted."
         unable_to_delete_the_administrator: "Unable to delete the administrator."
         add_a_group: "Add a group"
diff --git a/config/locales/app.admin.fr.yml b/config/locales/app.admin.fr.yml
index 510652ebc..8926a4cb7 100644
--- a/config/locales/app.admin.fr.yml
+++ b/config/locales/app.admin.fr.yml
@@ -336,6 +336,7 @@ fr:
         groups: "Groupes"
         authentication: "Authentification"
         do_you_really_want_to_delete_this_administrator_this_cannot_be_undone: "Êtes-vous sûr de vouloir supprimer cet administrateur ? Cette opération est irréversible."
+        this_may_take_a_while_please_wait: "Attention : ceci peut prendre un certain temps, merci de patienter."
         administrator_successfully_deleted: "L'administrateur a bien été supprimé."
         unable_to_delete_the_administrator: "L'administrateur n'a pas pu être supprimé."
         add_a_group: "Ajouter un groupe"
diff --git a/config/locales/app.shared.en.yml b/config/locales/app.shared.en.yml
index 8913ea48e..ffa74c5b3 100644
--- a/config/locales/app.shared.en.yml
+++ b/config/locales/app.shared.en.yml
@@ -324,6 +324,11 @@ en:
         credit_title: 'Credit wallet'
         credit_label: 'Set the amount to be credited'
         confirm_credit_label: 'Confirm the amount to be credited'
+        generate_a_refund_invoice: "Generate a refund invoice"
+        creation_date_for_the_refund: "Creation date for the refund"
+        creation_date_is_required: "Creation date is required."
+        description_(optional): "Description (optional):"
+        will_appear_on_the_refund_invoice: "Will appear on the refund invoice."
         to_credit: 'Credit'
         wallet_credit_successfully: "Wallet of user is credited successfully."
         a_problem_occurred_for_wallet_credit: "A problem is occurred while taking the credit of wallet"
diff --git a/config/locales/app.shared.fr.yml b/config/locales/app.shared.fr.yml
index fa1cdb010..3f83f502f 100644
--- a/config/locales/app.shared.fr.yml
+++ b/config/locales/app.shared.fr.yml
@@ -324,6 +324,11 @@ fr:
         credit_title: 'Créditer le porte-monnaie'
         credit_label: 'Indiquez le montant à créditer'
         confirm_credit_label: 'Confirmez le montant à créditer'
+        generate_a_refund_invoice: "Générer une facture d'avoir"
+        creation_date_for_the_refund: "Date d'émission de l'avoir"
+        creation_date_is_required: "La date d'émission est requise."
+        description_(optional): "Description (optionnelle) :"
+        will_appear_on_the_refund_invoice: "Apparaîtra sur la facture de remboursement."
         to_credit: 'Créditer'
         wallet_credit_successfully: "Le porte-monnaie de l'utilisateur a été chargé avec succès."
         a_problem_occurred_for_wallet_credit: "Un problème est survenu lors du chargement du porte-monnaie."
diff --git a/config/locales/en.yml b/config/locales/en.yml
index f30febc5e..56ff141a4 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -32,6 +32,10 @@ en:
       size_too_small: "is too small (should be at least %{file_size})"
       size_too_big: "is too big (should be at most %{file_size})"
       export_not_found: "Requested export was not found. It was probably deleted, please generate a new export."
+      percentage_out_of_range: "Percentage must be included between 0 and 100"
+      cannot_be_blank_at_same_time: "cannot be blank when %{field} is blank too"
+      cannot_be_in_the_past: "cannot be in the past"
+      cannot_be_before_previous_value: "cannot be before the previous value"
 
   activemodel:
     errors:
@@ -68,6 +72,7 @@ en:
     order_number: "Order #: %{NUMBER}"
     invoice_issued_on_DATE: "Invoice issued on %{DATE}"
     refund_invoice_issued_on_DATE: "Refund invoice issued on %{DATE}"
+    wallet_credit: "Wallet credit"
     cancellation_of_invoice_REF: "Cancellation of invoice %{REF}"
     reservation_of_USER_on_DATE_at_TIME: "Reservation of %{USER} on %{DATE} at %{TIME}"
     cancellation: "Cancellation"
diff --git a/config/locales/fr.yml b/config/locales/fr.yml
index 68bb7179c..5a17e3fa4 100644
--- a/config/locales/fr.yml
+++ b/config/locales/fr.yml
@@ -32,6 +32,10 @@ fr:
       size_too_small: "est trop petite (au moins %{file_size})"
       size_too_big: "est trop grande (pas plus de %{file_size})"
       export_not_found: "L'export demandé n'a pas été trouvé. Il a probablement été supprimé, veuillez lancer la génération d'un nouvel export."
+      percentage_out_of_range: "Le pourcentage doit être inclus entre 0 et 100"
+      cannot_be_blank_at_same_time: "ou %{field} doit être rempli(e)"
+      cannot_be_in_the_past: "ne peut pas être dans le passé"
+      cannot_be_before_previous_value: "ne peut pas être antérieur(e) à la valeur précédente"
 
   activemodel:
     errors:
@@ -68,6 +72,7 @@ fr:
     order_number: "N° Commande : %{NUMBER}"
     invoice_issued_on_DATE: "Facture éditée le %{DATE}"
     refund_invoice_issued_on_DATE: "Avoir édité le %{DATE}"
+    wallet_credit: "Crédit du porte-monnaie"
     cancellation_of_invoice_REF: "Annulation de la facture %{REF}"
     reservation_of_USER_on_DATE_at_TIME: "Réservation de %{USER} le %{DATE} à %{TIME}"
     cancellation: "Annulation"
diff --git a/db/migrate/20160906145713_insert_custom_aggregations.rb b/db/migrate/20160906145713_insert_custom_aggregations.rb
deleted file mode 100644
index 2e28fd5f1..000000000
--- a/db/migrate/20160906145713_insert_custom_aggregations.rb
+++ /dev/null
@@ -1,42 +0,0 @@
-class InsertCustomAggregations < ActiveRecord::Migration
-  def up
-    # available reservations hours for machines
-    machine = StatisticIndex.find_by(es_type_key: 'machine')
-    machine_hours = StatisticType.find_by(key: 'hour', statistic_index_id: machine.id)
-
-    available_hours = StatisticCustomAggregation.new({
-      statistic_type_id: machine_hours.id,
-      es_index: 'fablab',
-      es_type: 'availabilities',
-      field: 'available_hours',
-      query: '{"size":0, "aggregations":{"%{aggs_name}":{"sum":{"field":"hours_duration"}}}, "query":{"bool":{"must":[{"range":{"start_at":{"gte":"%{start_date}", "lte":"%{end_date}"}}}, {"match":{"available_type":"machines"}}]}}}'
-    })
-    available_hours.save!
-
-    # available training tickets
-    training = StatisticIndex.find_by(es_type_key: 'training')
-    training_bookings = StatisticType.find_by(key: 'booking', statistic_index_id: training.id)
-
-    available_tickets = StatisticCustomAggregation.new({
-      statistic_type_id: training_bookings.id,
-      es_index: 'fablab',
-      es_type: 'availabilities',
-      field: 'available_tickets',
-      query: '{"size":0, "aggregations":{"%{aggs_name}":{"sum":{"field":"nb_total_places"}}}, "query":{"bool":{"must":[{"range":{"start_at":{"gte":"%{start_date}", "lte":"%{end_date}"}}}, {"match":{"available_type":"training"}}]}}}'
-    })
-    available_tickets.save!
-  end
-
-  def down
-
-    machine = StatisticIndex.find_by(es_type_key: 'machine')
-    machine_hours = StatisticType.find_by(key: 'hour', statistic_index_id: machine.id)
-
-    StatisticCustomAggregation.where(field: 'available_hours', statistic_type_id: machine_hours.id).first.destroy!
-
-    training = StatisticIndex.find_by(es_type_key: 'training')
-    training_bookings = StatisticType.find_by(key: 'booking', statistic_index_id: training.id)
-
-    StatisticCustomAggregation.where(field: 'available_tickets', statistic_type_id: training_bookings.id).first.destroy!
-  end
-end
diff --git a/db/seeds.rb b/db/seeds.rb
index 33ee91648..c10636074 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -396,4 +396,30 @@ unless Setting.find_by(name: 'reminder_delay').try(:value)
   setting = Setting.find_or_initialize_by(name: 'reminder_delay')
   setting.value = '24'
   setting.save
+end
+
+if StatisticCustomAggregation.count == 0
+  # available reservations hours for machines
+  machine_hours = StatisticType.find_by(key: 'hour', statistic_index_id: 2)
+
+  available_hours = StatisticCustomAggregation.new({
+                       statistic_type_id: machine_hours.id,
+                       es_index: 'fablab',
+                       es_type: 'availabilities',
+                       field: 'available_hours',
+                       query: '{"size":0, "aggregations":{"%{aggs_name}":{"sum":{"field":"hours_duration"}}}, "query":{"bool":{"must":[{"range":{"start_at":{"gte":"%{start_date}", "lte":"%{end_date}"}}}, {"match":{"available_type":"machines"}}]}}}'
+                    })
+  available_hours.save!
+
+  # available training tickets
+  training_bookings = StatisticType.find_by(key: 'booking', statistic_index_id: 3)
+
+  available_tickets = StatisticCustomAggregation.new({
+                         statistic_type_id: training_bookings.id,
+                         es_index: 'fablab',
+                         es_type: 'availabilities',
+                         field: 'available_tickets',
+                         query: '{"size":0, "aggregations":{"%{aggs_name}":{"sum":{"field":"nb_total_places"}}}, "query":{"bool":{"must":[{"range":{"start_at":{"gte":"%{start_date}", "lte":"%{end_date}"}}}, {"match":{"available_type":"training"}}]}}}'
+                      })
+  available_tickets.save!
 end
\ No newline at end of file
diff --git a/docker/README.md b/docker/README.md
index ad53b0587..1d1855bd3 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -125,7 +125,7 @@ Requires=docker.service
 [Service]
 Type=oneshot  
 ExecStart=/usr/bin/docker run --rm --name letsencrypt -v "/home/core/fabmanager/log:/var/log/letsencrypt" -v "/home/core/fabmanager/letsencrypt/etc:/etc/letsencrypt" -v "/home/core/fabmanager/letsencrypt/config:/letsencrypt-config" quay.io/letsencrypt/letsencrypt:latest -c "/letsencrypt-config/webroot.ini" certonly
-ExecStartPost=-/usr/bin/docker restart fabmanager  
+ExecStartPost=-/usr/bin/docker restart fabmanager_nginx_1  
 ```
 
 Create file (with sudo) /etc/systemd/system/letsencrypt.timer with
@@ -138,6 +138,9 @@ Requires=docker.service
 OnCalendar=*-*-1 06:00:00
 Persistent=true
 Unit=letsencrypt.service
+
+[Install]
+WantedBy=timers.target
 ```
 
 Then deploy your app and read the "Generate SSL certificate by Letsencrypt" section to complete the installation of the letsencrypt certificate.
@@ -277,7 +280,9 @@ Remove your app and Run your app to apply changes
 Finally, if everything is ok, start letsencrypt timer to update the certificate every 1st of the month :
 
 ```bash
+sudo systemctl enable letsencrypt.timer
 sudo systemctl start letsencrypt.timer
+(check) sudo systemctl list-timers
 ```
 
 
diff --git a/test/integration/events/as_user_test.rb b/test/integration/events/as_user_test.rb
index 8b32e4fca..cf1239cba 100644
--- a/test/integration/events/as_user_test.rb
+++ b/test/integration/events/as_user_test.rb
@@ -1,7 +1,7 @@
 module Events
   class AsUserTest < ActionDispatch::IntegrationTest
 
-    test 'reserve event with many prices and payment means' do
+    test 'reserve event with many prices and payment means and VAT' do
 
       vlonchamp = User.find_by(username: 'vlonchamp')
       login_as(vlonchamp, scope: :user)
@@ -15,6 +15,15 @@ module Events
       users_credit_count = UsersCredit.count
       wallet_transactions_count = WalletTransaction.count
 
+      # Enable the VAT at 19.6%
+      vat_active = Setting.find_by(name: 'invoice_VAT-active')
+      vat_active.value = 'true'
+      vat_active.save!
+
+      vat_rate = Setting.find_by(name: 'invoice_VAT-rate')
+      vat_rate.value = '19.6'
+      vat_rate.save!
+
       # Reserve the 'radio' event
       VCR.use_cassette('reserve_event_with_many_prices_and_payment_means') do
         post reservations_path, {
diff --git a/test/integration/prices/compute_test.rb b/test/integration/prices/compute_test.rb
new file mode 100644
index 000000000..3a0231964
--- /dev/null
+++ b/test/integration/prices/compute_test.rb
@@ -0,0 +1,82 @@
+module Events
+  class AsAdminTest < ActionDispatch::IntegrationTest
+
+    setup do
+      admin = User.with_role(:admin).first
+      login_as(admin, scope: :user)
+    end
+
+    test 'compute price for a simple training' do
+      user = User.find_by(username: 'jdupond')
+      availability = Availability.find(2)
+      printer_training = availability.trainings.first
+
+      post '/api/prices/compute',
+           {
+               reservation: {
+                   user_id: user.id,
+                   reservable_id: printer_training.id,
+                   reservable_type: printer_training.class.name,
+                   slots_attributes: [
+                       {
+                           availability_id: availability.id,
+                           end_at: availability.end_at,
+                           offered: false,
+                           start_at: availability.start_at
+                       }
+                   ]
+               }
+           }.to_json,
+           default_headers
+
+      # Check response format & status
+      assert_equal 200, response.status, response.body
+      assert_equal Mime::JSON, response.content_type
+
+      # Check the price was computed correctly
+      price = json_response(response.body)
+      assert_equal (printer_training.trainings_pricings.where(group_id: user.group_id).first.amount / 100.0), price[:price], 'Computed price did not match training price'
+    end
+
+
+    test 'compute price for a machine reservation with an offered slot and a subscription' do
+      user = User.find_by(username: 'jdupond')
+      availability = Availability.find(3)
+      laser = availability.machines.where(id: 1).first
+      plan = Plan.where(group_id: user.group_id, interval: 'month').first
+
+      post '/api/prices/compute',
+           {
+               reservation: {
+                   user_id: user.id,
+                   reservable_id: laser.id,
+                   reservable_type: laser.class.name,
+                   plan_id: plan.id,
+                   slots_attributes: [
+                       {
+                           availability_id: availability.id,
+                           end_at: (availability.start_at + 1.hour).strftime('%Y-%m-%d %H:%M:%S.%9N Z'),
+                           offered: true,
+                           start_at: availability.start_at.strftime('%Y-%m-%d %H:%M:%S.%9N Z')
+                       },
+                       {
+                           availability_id: availability.id,
+                           end_at: (availability.start_at + 2.hour).strftime('%Y-%m-%d %H:%M:%S.%9N Z'),
+                           offered: false,
+                           start_at: (availability.start_at + 1.hour).strftime('%Y-%m-%d %H:%M:%S.%9N Z')
+                       }
+                   ]
+               }
+           }.to_json,
+           default_headers
+
+      # Check response format & status
+      assert_equal 200, response.status, response.body
+      assert_equal Mime::JSON, response.content_type
+
+      # Check the event was created correctly
+      price = json_response(response.body)
+      assert_equal ((laser.prices.where(group_id: user.group_id, plan_id: plan.id).first.amount + plan.amount) / 100.0), price[:price], 'Computed price did not match machine + subscription price'
+    end
+  end
+end
diff --git a/test/integration/wallets_test.rb b/test/integration/wallets_test.rb
index 19a68a1fa..d279edc28 100644
--- a/test/integration/wallets_test.rb
+++ b/test/integration/wallets_test.rb
@@ -74,5 +74,38 @@ class WalletsTest < ActionDispatch::IntegrationTest
     w.reload
     assert_equal w.amount, expected_amount
     assert_equal w.amount, wallet[:amount]
+
+    # no refund invoices should have been generated
+    assert_empty Invoice.where(invoiced: w.wallet_transactions.last)
+  end
+
+
+  test 'admin credit wallet with refund invoice generation' do
+    admin = users(:user_1)
+    login_as(admin, scope: :user)
+    w = @vlonchamp.wallet
+    amount = 10
+    avoir_date = Time.now.end_of_day
+    expected_amount = w.amount + amount
+    put "/api/wallet/#{w.id}/credit",
+        {
+            amount: amount,
+            avoir: true,
+            avoir_date: avoir_date,
+            avoir_description: 'Some text'
+        }
+
+    assert_equal 200, response.status
+    assert_equal Mime::JSON, response.content_type
+    wallet = json_response(response.body)
+    w.reload
+    assert_equal w.amount, expected_amount
+    assert_equal w.amount, wallet[:amount]
+
+    # refund invoice must be generated
+    invoice = Invoice.where(invoiced: w.wallet_transactions.last).first
+    assert_equal amount, (invoice.total / 100.0), 'Avoir total does not match the amount credited to the wallet'
+    assert_equal amount, (invoice.invoice_items.first.amount / 100.0), 'Invoice item amount does not match'
+    assert_invoice_pdf invoice
   end
 end
diff --git a/test/models/coupon_test.rb b/test/models/coupon_test.rb
index f1cef7ee7..1c8ade1a5 100644
--- a/test/models/coupon_test.rb
+++ b/test/models/coupon_test.rb
@@ -1,6 +1,14 @@
 require 'test_helper'
 
 class CouponTest < ActiveSupport::TestCase
+
+  test 'valid coupon with percentage' do
+    c = Coupon.new({name: 'Hot deals', code: 'HOT15', percent_off: 15, validity_per_user: 'once', valid_until: (Time.now + 2.weeks), max_usages: 100, active: true})
+    assert c.valid?
+    assert_equal 'active', c.status, 'Invalid coupon status'
+    assert_equal 'percent_off', c.type, 'Invalid coupon type'
+  end
+
   test 'coupon must have a valid percentage' do
     c = Coupon.new({name: 'Amazing deal', code: 'DISCOUNT', percent_off: 200, validity_per_user: 'once'})
     assert c.invalid?
@@ -16,9 +24,11 @@ class CouponTest < ActiveSupport::TestCase
     assert c.invalid?
   end
 
-  test 'coupon with cash amount has amount_off type' do
-    c = Coupon.new({name: 'Essential Box', code: 'KWXX2M', amount_off: 2000, validity_per_user: 'once', max_usages: 1})
-    assert_equal 'amount_off', c.type
+  test 'valid coupon with cash amount' do
+    c = Coupon.new({name: 'Essential Box', code: 'KWXX2M', amount_off: 2000, validity_per_user: 'once', max_usages: 1, active: true})
+    assert c.valid?
+    assert_equal 'active', c.status, 'Invalid coupon status'
+    assert_equal 'amount_off', c.type, 'Invalid coupon type'
   end
 
   test 'coupon with cash amount cannot be used with cheaper cart' do
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 792006eac..4b7c20e5e 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,3 +1,6 @@
+require 'coveralls'
+Coveralls.wear!('rails')
+
 ENV['RAILS_ENV'] ||= 'test'
 require File.expand_path('../../config/environment', __FILE__)
 require 'rails/test_help'
@@ -68,6 +71,33 @@ class ActiveSupport::TestCase
 
     assert File.exist?(invoice.file), 'Invoice PDF was not generated'
 
+    # now we check the file content
+    reader = PDF::Reader.new(invoice.file)
+    assert_equal 1, reader.page_count # single page invoice
+
+    ht_amount = invoice.total
+    page = reader.pages.first
+    lines = page.text.scan(/^.+/)
+    lines.each do |line|
+      # check that the numbers printed into the PDF file match the total stored in DB
+      if line.include? I18n.t('invoices.total_amount')
+        assert_equal invoice.total / 100.0, parse_amount_from_invoice_line(line), 'Invoice total rendered in the PDF file does not match'
+      end
+
+      # check that the VAT was correctly applied if it was configured
+      if line.include? I18n.t('invoices.including_total_excluding_taxes')
+        ht_amount = parse_amount_from_invoice_line(line)
+      end
+    end
+
+    if Setting.find_by(name: 'invoice_VAT-active').value == 'true'
+      vat_rate = Setting.find_by({name: 'invoice_VAT-rate'}).value.to_f
+      computed_ht = sprintf('%.2f', (invoice.total / (vat_rate / 100 + 1)) / 100.0).to_f
+
+      assert_equal computed_ht, ht_amount, 'Total excluding taxes rendered in the PDF file is not computed correctly'
+    else
+      assert_equal invoice.total, ht_amount, 'VAT information was rendered in the PDF file despite that VAT was disabled'
+    end
     File.delete(invoice.file)
   end
 
@@ -89,6 +119,15 @@ class ActiveSupport::TestCase
       skip('Unable to test export which is not of the category "statistics"')
     end
   end
+
+  private
+
+  # Parse a line of text read from a PDF file and return the price included inside
+  # Line of text should be of form 'Label              $10.00'
+  # @returns {float}
+  def parse_amount_from_invoice_line line
+    line[line.rindex(' ')+1..-1].tr(I18n.t('number.currency.format.unit'), '').to_f
+  end
 end
 
 class ActionDispatch::IntegrationTest