diff --git a/kfet/config.py b/kfet/config.py
index 5023e8b0..76da5a79 100644
--- a/kfet/config.py
+++ b/kfet/config.py
@@ -16,6 +16,11 @@ class KFetConfig(object):
     prefix = 'kfet_'
 
     def __getattr__(self, key):
+        if key == 'subvention_cof':
+            # Allows accessing to the reduction as a subvention
+            # Other reason: backward compatibility
+            reduction_mult = 1 - self.reduction_cof/100
+            return (1/reduction_mult - 1) * 100
         return getattr(config, self._get_dj_key(key))
 
     def list(self):
diff --git a/kfet/forms.py b/kfet/forms.py
index 9b098b75..f89b8f08 100644
--- a/kfet/forms.py
+++ b/kfet/forms.py
@@ -403,17 +403,20 @@ class AddcostForm(forms.Form):
 
 class KFetConfigForm(ConfigForm):
 
-    kfet_subvention_cof = forms.DecimalField(
-        label='Subvention COF', initial=Decimal('25'),
+    kfet_reduction_cof = forms.DecimalField(
+        label='Réduction COF', initial=Decimal('20'),
         max_digits=6, decimal_places=2,
+        help_text="Réduction, à donner en pourcentage, appliquée lors d'un "
+                  "achat par un-e membre du COF sur le montant en euros.",
     )
     kfet_addcost_amount = forms.DecimalField(
-        label='Montant de la majoration', initial=Decimal('0'), required=False,
+        label='Montant de la majoration (en €)', initial=Decimal('0'),
+        required=False,
         max_digits=6, decimal_places=2,
     )
     kfet_addcost_for = forms.ModelChoiceField(
         label='Destinataire de la majoration', initial=None, required=False,
-        help_text='Laissez vide pour désactiver la majoration',
+        help_text='Laissez vide pour désactiver la majoration.',
         queryset=(Account.objects
                   .select_related('cofprofile', 'cofprofile__user')
                   .all()),
@@ -423,7 +426,8 @@ class KFetConfigForm(ConfigForm):
         initial=timedelta(days=1),
     )
     kfet_overdraft_amount = forms.DecimalField(
-        label='Montant du découvert autorisé par défaut', initial=Decimal('20'),
+        label='Montant du découvert autorisé par défaut (en €)',
+        initial=Decimal('20'),
         max_digits=6, decimal_places=2,
     )
     kfet_cancel_duration = forms.DurationField(
diff --git a/kfet/migrations/0054_delete_settings.py b/kfet/migrations/0054_delete_settings.py
index 7a0b1ab8..80ee1d24 100644
--- a/kfet/migrations/0054_delete_settings.py
+++ b/kfet/migrations/0054_delete_settings.py
@@ -21,7 +21,13 @@ def adapt_settings(apps, schema_editor):
         except Settings.DoesNotExist:
             pass
 
-    try_get('kfet_subvention_cof', 'SUBVENTION_COF', 'value_decimal')
+    try:
+        subvention = obj.get(name='SUBVENTION_COF').value_decimal
+        subvention_mult = 1 + subvention/100
+        reduction = (1 - 1/subvention_mult) * 100
+        cfg['kfet_reduction_cof'] = reduction
+    except Settings.DoesNotExist:
+        pass
     try_get('kfet_addcost_amount', 'ADDCOST_AMOUNT', 'value_decimal')
     try_get('kfet_addcost_for', 'ADDCOST_FOR', 'value_account')
     try_get('kfet_overdraft_duration', 'OVERDRAFT_DURATION', 'value_duration')