| 400 | Bad Request | The request is malformed or missing the required fields. |
| 400 | Bad Request | One or more fields in the request failed validation. |
| 401 | Unauthorized | Invalid credentials. |
| 403 | Forbidden | Your credentials do not have permission to perform this action. |
| 404 | Not Found | The requested resource does not exist. |
| 409 | Conflict | Payment with this end-to-end ID already exists. |
| 422 | Unprocessable Entity | Payment object is invalid for the selected provider. |
| 429 | Too Many Requests | Too many requests have been sent in a short period of time. |
| 500 | Internal Server Error | An unexpected error occurred. |
| 503 | Service Unavailable | The service is temporarily unavailable, usually due to maintenance or overload. |