# HTTP response errors

The Merchant API uses the following error codes:

| Error code | Description                                                                                                                                                                                                                                                                |
| ---------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `400`      | Bad Request -- Your request is invalid. Ensure that all the parameters provided in the request follow the [API Reference](/docs/api/merchant).                                                                                                                             |
| `401`      | Unauthorized -- Your access token is wrong.                                                                                                                                                                                                                                |
| `403`      | Forbidden -- Access to the requested resource or action is forbidden.                                                                                                                                                                                                      |
| `404`      | Not Found -- The requested resource could not be found.                                                                                                                                                                                                                    |
| `405`      | Method Not Allowed -- You tried to access an endpoint with an invalid method.                                                                                                                                                                                              |
| `406`      | Not Acceptable -- You requested a format that isn't JSON.                                                                                                                                                                                                                  |
| `422`      | Unprocessable entity -- Your request is incorrect. This can happen when you're trying to perform an operation that is invalid. For example, trying to use the [Capture an order](/docs/api/merchant#capture-order) endpoint on an order that is not in `authorised` state. |
| `429`      | Too Many Requests -- You're sending too many requests.                                                                                                                                                                                                                     |
| `500`      | Internal Server Error -- We had a problem with our server. Try again later.                                                                                                                                                                                                |
| `503`      | Service Unavailable -- We're temporarily offline for maintenance. Please try again later.                                                                                                                                                                                  |