# Codes and formats
source: https://developer.mastercard.com/mastercard-supplier-payment-agent/documentation/codes-and-messages/index.md

## HTTPS response codes {#https-response-codes}

| Status Code |         Description          |
|-------------|------------------------------|
| 200         | OK                           |
| 201         | Payment Instructions Created |
| 401         | Unauthorized                 |
| 403         | Forbidden                    |
| 404         | Not Found                    |

## Gateway error codes {#gateway-error-codes}

Refer to the [Gateway Error Codes](https://developer.mastercard.com/platform/documentation/gateway-error-codes/) page for more information on errors you may encounter with the gateway.