CLIENT_DUPLICATE
A client with this NIF already exists
Category: Customers
| HTTP status | 409 Conflict |
Example response
When this error occurs, the API answers 409 Conflict with a JSON body of this shape:
{
"type": "https://docs.beel.es/errors/CLIENT_DUPLICATE",
"title": "CLIENT_DUPLICATE",
"detail": "A client with this NIF already exists",
"instance": "/v1/<resource>",
"errors": [],
"success": false,
"error": {
"code": "CLIENT_DUPLICATE",
"message": "A client with this NIF already exists",
"details": {}
},
"meta": {
"timestamp": "2026-05-21T10:00:00Z",
"request_id": "4bf92f3577b34da6a3ce929d0e0e4736"
}
}The type URI is stable and always resolves to this page.
Message
Send the request with Accept-Language: <es|en|ca> to receive the message in your preferred language.
Other errors in this category
ALTERNATIVE_ID_ACTUALLY_IN_CENSUS
The identifier '‹value›' is registered in the AEAT census, so it cannot be declared as not registered (07). Enter it as a NIF instead.
ALTERNATIVE_ID_AND_NIF_EXCLUSIVE
The customer cannot carry both a NIF and an alternative identifier. Use only one
ALTERNATIVE_ID_COUNTRY_REQUIRED
The country of the alternative identifier is missing (alternative_id.country_code). It is required except for the PASSPORT and NOT_REGISTERED types, which are taken as Spanish when it is omitted.
ALTERNATIVE_ID_INVALID
The alternative identifier is not valid
ALTERNATIVE_ID_REQUIRES_SPAIN
Type NOT_REGISTERED (07) is only valid for Spain; received country: '‹value›'
Keep exploring
CLAIM_TOKEN_HOLDER_MISMATCH
That account already has a holder with a different email. Omit the field to re-issue the link to them.
CLIENT_HAS_INVOICES
This customer has invoices and cannot be deleted: deleting it would release its identifier and allow another customer to be created with the same one, splitting a single identity across two records. To stop using it, deactivate it with active:false