CUSTOMER_DUPLICATED_IN

Customer with a NIF/CIF duplicated in the file

Category: Customers


Retry	After fixing the cause

When it happens

A row of the file has the same NIF as an earlier row of the same file. It is reported in the row's errors.

How to fix it

Keep one row per customer in the file and import it again.

Retry

Not as is: the same request fails the same way. Fix the cause described above, then send the request again, under a new Idempotency-Key if the body changed.

Returned by

The operations where this code is most likely. The list is not exhaustive.

Example response

When this error occurs, the API returns a JSON response with the following shape:

{
  "type": "https://docs.beel.es/errors/CUSTOMER_DUPLICATED_IN_FILE",
  "title": "CUSTOMER_DUPLICATED_IN_FILE",
  "detail": "Customer with a NIF/CIF duplicated in the file",
  "instance": "/v1/<resource>",
  "errors": [],
  "success": false,
  "error": {
    "code": "CUSTOMER_DUPLICATED_IN_FILE",
    "message": "Customer with a NIF/CIF duplicated in the file",
    "details": {}
  },
  "meta": {
    "timestamp": "2026-05-21T10:00:00Z",
    "request_id": "4bf92f3577b34da6a3ce929d0e0e4736"
  }
}

The type URI is stable and always resolves to this page.

Message

Customer with a NIF/CIF duplicated in the file

Cliente con NIF/CIF duplicado en el archivo

Client amb NIF/CIF duplicat al fitxer

Send the request with Accept-Language: <es|en|ca> to receive the message in your preferred language.

Other errors in this category

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›'

ALTERNATIVE_ID_SPAIN_INVALID_TYPE

For customers with country ES only types PASSPORT (03) or NOT_REGISTERED (07) are allowed

CUSTOMER_DUPLICATED_IN_FILE