> For the complete documentation index, see [llms.txt](https://docs.tebex.io/developers/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tebex.io/developers/checkout-api/errors.md).

# Errors

All errors returned by the Tebex Checkout APIs follow the RFC 7807 standard (<https://datatracker.ietf.org/doc/html/rfc7807#section-3.1>).

We also use standardised HTTP response codes to describe each error:

1. **400 Bad Request** - User data validation error
2. **401 / 403 - Authentication / Authorization** (depending on if it's pre- or post- authentication
3. **404** - Requested resource doesn't exist
4. **5xx** - Server side transitory errors.

```javascript
{
  "type": "Not Found",
  "title": "Resource not found",
  "status": 404,
  "detail": "The requested resource does not exist.",
  "instance": "/account/12345"
}
```