# Error Codes
source: https://developer.mastercard.com/account-to-account-commerce-for-csp/documentation/code-and-formats/error-codes/index.md

### Technical Error Codes {#technical-error-codes}

The following table contains errors returned by services external to Zapp Platform. External
services return these codes when there are errors on the component serving the request.

| HTTP Status Code | Error Code |                                                                                                                                                                                                                                                                    Code Description                                                                                                                                                                                                                                                                     |
|------------------|------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 400              | STVL-9999  | Invalid structure: The header or payload fails syntax or structural validation.                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| 401              | SECU-9999  | Invalid signature: The service fails signature validation.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| 403              | SECU-9998  | Access forbidden: The service fails authorization checks to access a resource.                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| 500              | TECH-9999  | Internal server error: Zapp Platform sends this error when the component implementing the external service experiences any of the following: - Times out when calling a downstream system. - Has an internal service error due to misconfigurations. - Fails to validate the information received from edge devices such as JWT auth header transmitted by the API Gateway. - Has any other server side errors that prevent the component from serving the request and the error cannot be covered under the other HTTP status codes, for example, 503. |

#### HTTP Status Code and Description {#http-status-code-and-description}

| HTTP status Code | Response |               Description               |
|------------------|----------|-----------------------------------------|
| 200              | OK       | The request was completed successfully. |

### Error Code Format {#error-code-format}

All errors that Account to Account Commerce APIs return, have the following format.

    { 
        "Errors": { 
            "Error": [ 
                { 
                    "Source": "<source>", 
                    "ReasonCode": "<unique code>",
                    "Description": "<short description of the error>", 
                    "Recoverable": true/false, 
                    "Details": "<optional detailed description of the issue>" 
                } 
            ] 
        } 
    } 

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

Apart from the error codes returned by the ID for the TP API, other error codes can be returned by the Mastercard gateway, which verifies your request's signature and routes it to the correct location.   

For further information about the 4xx response codes returned by the gateway and their possible resolutions, see [Gateway Error Codes](https://developer.mastercard.com/platform/documentation/security-and-authentication/gateway-error-codes/).