diff --git a/src/application/commands/create_payment_cloudkassir_command.py b/src/application/commands/create_payment_cloudkassir_command.py
index d62864a..2e38ae7 100644
--- a/src/application/commands/create_payment_cloudkassir_command.py
+++ b/src/application/commands/create_payment_cloudkassir_command.py
@@ -65,7 +65,7 @@ class CreatePaymentCloudkassirCommand:
             raise ApplicationException(status_code=400, message='User inn missing')
         if user.birth_date is None:
             raise ApplicationException(status_code=400, message='User birth date missing')
-        customer_birthday = user.birth_date.isoformat()
+        customer_birthday = f'{user.birth_date.isoformat()}T12:00:00.000Z'
 
         paid_total = _parse_money(payment.amount)
         if paid_total is None: