diff --git a/api/v1/serializers/config.py b/api/v1/serializers/config.py
index ef7b3f1a..af2bb0cb 100644
--- a/api/v1/serializers/config.py
+++ b/api/v1/serializers/config.py
@@ -16,6 +16,7 @@ class ConfigSerializer(serializers.Serializer):
     INSTAGRAM_CLIENT_ACCESS_TOKEN = serializers.CharField(required=False)
     INSTAGRAM_CLIENT_SECRET = serializers.CharField(required=False)
     SERVICE_COMMISSION = serializers.IntegerField(required=False)
+    SERVICE_DISCOUNT_MIN_AMOUNT = serializers.IntegerField(required=False)
     SERVICE_DISCOUNT = serializers.IntegerField(required=False)
 
     def to_representation(self, instance):
diff --git a/apps/payment/models.py b/apps/payment/models.py
index b6c220b9..5ec8e1ac 100644
--- a/apps/payment/models.py
+++ b/apps/payment/models.py
@@ -157,7 +157,7 @@ class SchoolPayment(Payment):
             models.Sum('month_price'),
         )
         month_price_sum = aggregate.get('month_price__sum', 0)
-        if month_price_sum >= config.SERVICE_DISCOUNT_MIN_AMOUNT:
+        if len(self.weekdays) > 7:
             discount = config.SERVICE_DISCOUNT
         else:
             discount = 0