diff --git a/config.ru b/config.ru
index 2fdb5e25c15fd44f621d1cc098eed14979d52641..7e6b90595d0418389f718431e0efec89297483d3 100644
--- a/config.ru
+++ b/config.ru
@@ -134,10 +134,18 @@ class CreditCardGateway
 		end
 	end
 
+	def payment_method_create_options
+		options = { verify_card: true, make_default: true }
+		if merchant_account
+			options[:verification_merchant_account_id] = merchant_account.to_s
+		end
+		options
+	end
+
 	def default_method(nonce)
 		result = antifraud || @gateway.payment_method.create(
 			customer_id: customer_id, payment_method_nonce: nonce,
-			options: { verify_card: true, make_default: true }
+			options: payment_method_create_options
 		)
 
 		return result if result.success?