# HTTP response status codes

| Code | Description |
|  --- | --- |
| 200/201 | OK. Everything worked as expected. |
| 204 | OK. Everything worked OK but no values were returned. |
| 400 | Bad request. The request you made was not accepted. This can be due to issues including missing a required parameter. |
| 401 | Unauthorized. Occurs for issues with authentication such as you didn't provide a token or the token you provided does not exist. |
| 404 | Not found. The requested resource doesn’t exist. |
| 409 | Conflict.  There was a conflict in your request. This could be caused by things like too many concurrent calls or if you tried to create a duplicate address in your address book. |
| 422 | Unprocessable entity . Your request contained content that could not be processed by the Shippo API. |
| 429 | Rate limit exceeded. You have made too many requests to the Shippo API. See our [rates limit guide](/docs/api_concepts/ratelimits). |
| 5xx | Server error. Something has gone wrong with the Shippo server. |