diff --git a/app/models/price.rb b/app/models/price.rb
index ddb95a6d3..1f3e6468f 100644
--- a/app/models/price.rb
+++ b/app/models/price.rb
@@ -112,7 +112,7 @@ class Price < ActiveRecord::Base
 
     # === apply Coupon if any ===
     _amount_no_coupon = _amount
-    _amount = CouponApplyService.new.(_amount, coupon_code)
+    _amount = CouponService.new.apply(_amount, coupon_code)
 
     # return result
     {elements: _elements, total: _amount, before_coupon: _amount_no_coupon}
diff --git a/app/models/reservation.rb b/app/models/reservation.rb
index 5f74e4b3c..7214597c4 100644
--- a/app/models/reservation.rb
+++ b/app/models/reservation.rb
@@ -409,7 +409,7 @@ class Reservation < ActiveRecord::Base
   def get_wallet_amount_debit
     total = get_cart_total
     if @coupon
-      total = CouponApplyService.new.(total, @coupon, user.id)
+      total = CouponService.new.apply(total, @coupon, user.id)
     end
     wallet_amount = (user.wallet.amount * 100).to_i
 
@@ -443,7 +443,7 @@ class Reservation < ActiveRecord::Base
     unless coupon_code.nil?
       cp = Coupon.find_by(code: coupon_code)
       if not cp.nil? and cp.status(user.id) == 'active'
-        total = CouponApplyService.new.(total, cp, user.id)
+        total = CouponService.new.apply(total, cp, user.id)
         self.invoice.coupon_id = cp.id
       else
         raise InvalidCouponError
diff --git a/app/models/subscription.rb b/app/models/subscription.rb
index b6224a6e0..dae9d6d4f 100644
--- a/app/models/subscription.rb
+++ b/app/models/subscription.rb
@@ -178,7 +178,7 @@ class Subscription < ActiveRecord::Base
       @coupon = Coupon.find_by(code: coupon_code)
 
       unless @coupon.nil?
-        total = CouponApplyService.new.(plan.amount, @coupon, user.id)
+        total = CouponService.new.apply(plan.amount, @coupon, user.id)
         coupon_id = @coupon.id
       end
     end
@@ -309,7 +309,7 @@ class Subscription < ActiveRecord::Base
   def get_wallet_amount_debit
     total = plan.amount
     if @coupon
-      total = CouponApplyService.new.(total, @coupon, user.id)
+      total = CouponService.new.apply(total, @coupon, user.id)
     end
     wallet_amount = (user.wallet.amount * 100).to_i
     return wallet_amount >= total ? total : wallet_amount
diff --git a/app/services/coupon_service.rb b/app/services/coupon_service.rb
index 0da03e83b..7600de148 100644
--- a/app/services/coupon_service.rb
+++ b/app/services/coupon_service.rb
@@ -1,4 +1,4 @@
-class CouponApplyService
+class CouponService
   ##
   # Apply the provided coupon, if active, to the given price. Usability tests will be run depending on the
   # provided parameters.
@@ -9,7 +9,7 @@ class CouponApplyService
   # @param user_id {Number} user's id against the coupon will be tested for usability
   # @return {Number}
   ##
-  def call(total, coupon, user_id = nil)
+  def apply(total, coupon, user_id = nil)
     price = total
 
     _coupon = nil
@@ -34,4 +34,27 @@ class CouponApplyService
 
     price
   end
+
+
+  ##
+  # Ventilate the discount of the provided coupon over the given amount proportionately to the invoice's total
+  # @param total {Number} total amount of the invoice expressed in monetary units
+  # @param amount {Number} price of the invoice's sub-item expressed in monetary units
+  # @param coupon {Coupon} coupon applied to the invoice, amount_off expressed in centimes if applicable
+  ##
+  def ventilate(total, amount, coupon)
+    price = amount
+    if !coupon.nil? and total != 0
+      if coupon.type == 'percent_off'
+        price = amount - ( amount * coupon.percent_off / 100.0 )
+      elsif coupon.type == 'amount_off'
+        ratio = (coupon.amount_off / 100.0) / total
+        discount = amount * ratio.abs
+        price = amount - discount
+      else
+        raise InvalidCouponError
+      end
+    end
+    price
+  end
 end
\ No newline at end of file
diff --git a/app/services/statistic_service.rb b/app/services/statistic_service.rb
index f22c47b26..b824e370e 100644
--- a/app/services/statistic_service.rb
+++ b/app/services/statistic_service.rb
@@ -127,7 +127,7 @@ class StatisticService
           if sub
             ca = i.amount.to_i / 100.0
             unless i.invoice.coupon_id.nil?
-              ca = CouponApplyService.new.(ca, i.invoice.coupon)
+              ca = CouponService.new.ventilate(get_invoice_total_no_coupon(i.invoice), ca, i.invoice.coupon)
             end
             u = sub.user
             p = sub.plan
@@ -261,7 +261,7 @@ class StatisticService
   def members_list(options = default_options)
     result = []
     User.with_role(:member).includes(:profile).where('users.created_at >= :start_date AND users.created_at <= :end_date', options).each do |u|
-      if !u.need_completion?
+      unless u.need_completion?
         result.push OpenStruct.new({
           date: options[:start_date].to_date
         }.merge(user_info(u)))
@@ -353,7 +353,7 @@ class StatisticService
     end
     # subtract coupon discount from invoices and refunds
     unless invoice.coupon_id.nil?
-      ca = CouponApplyService.new.(ca, invoice.coupon)
+      ca = CouponService.new.ventilate(get_invoice_total_no_coupon(invoice), ca, invoice.coupon)
     end
     # divide the result by 100 to convert from centimes to monetary unit
     ca == 0 ? ca : ca / 100.0
@@ -366,7 +366,7 @@ class StatisticService
     end
     # subtract coupon discount from the refund
     unless invoice.coupon_id.nil?
-      ca = CouponApplyService.new.(ca, invoice.coupon)
+      ca = CouponService.new.ventilate(get_invoice_total_no_coupon(invoice), ca, invoice.coupon)
     end
     ca == 0 ? ca : ca / 100.0
   end
@@ -451,6 +451,11 @@ class StatisticService
     user_subscription_ca.inject {|sum,x| sum.ca + x.ca } || 0
   end
 
+  def get_invoice_total_no_coupon(invoice)
+    total = (invoice.invoice_items.map(&:amount).map(&:to_i).reduce(:+) or 0)
+    total / 100.0
+  end
+
   def find_or_create_user_info_info_list(user, list)
     found = list.select do |l|
       l.user_id == user.id
diff --git a/test/services/coupon_service_test.rb b/test/services/coupon_service_test.rb
index f42db7f9c..884145caa 100644
--- a/test/services/coupon_service_test.rb
+++ b/test/services/coupon_service_test.rb
@@ -7,22 +7,22 @@ class CouponServiceTest < ActiveSupport::TestCase
   end
 
   test 'user apply percent coupon to cart' do
-    total = CouponService.new.(1000, 'SUNNYFABLAB', @jdupond.id)
+    total = CouponService.new.apply(1000, 'SUNNYFABLAB', @jdupond.id)
     assert_equal 850, total
   end
 
   test 'user cannot apply excessive coupon to cart' do
-    total = CouponService.new.(1000, @cash_coupon, @jdupond.id)
+    total = CouponService.new.apply(1000, @cash_coupon, @jdupond.id)
     assert_equal 1000, total
   end
 
   test 'user cannot apply invalid coupon to cart' do
-    total = CouponService.new.(1000, 'INVALIDCODE', @jdupond.id)
+    total = CouponService.new.apply(1000, 'INVALIDCODE', @jdupond.id)
     assert_equal 1000, total
   end
 
   test 'user cannot apply expired coupon to cart' do
-    total = CouponService.new.(1000, 'XMAS10', @jdupond.id)
+    total = CouponService.new.apply(1000, 'XMAS10', @jdupond.id)
     assert_equal 1000, total
   end
 end