# ALTERNATIVE_ID_AND_NIF_EXCLUSIVE

The customer cannot carry both a NIF and an alternative identifier. Use only one

<Callout type="info">
**Category:** [Customers](/errors/category/cliente)
</Callout>

## Example response

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

```json
{
  "type": "https://docs.beel.es/errors/ALTERNATIVE_ID_AND_NIF_EXCLUSIVE",
  "title": "ALTERNATIVE_ID_AND_NIF_EXCLUSIVE",
  "detail": "The customer cannot carry both a NIF and an alternative identifier. Use only one",
  "instance": "/v1/<resource>",
  "errors": [],
  "success": false,
  "error": {
    "code": "ALTERNATIVE_ID_AND_NIF_EXCLUSIVE",
    "message": "The customer cannot carry both a NIF and an alternative identifier. Use only one",
    "details": {}
  },
  "meta": {
    "timestamp": "2026-05-21T10:00:00Z",
    "request_id": "4bf92f3577b34da6a3ce929d0e0e4736"
  }
}
```

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

## Message

<Tabs items={["English", "Spanish", "Catalan"]}>
  <Tab value="English">{"The customer cannot carry both a NIF and an alternative identifier. Use only one"}</Tab>
  <Tab value="Spanish">{"El cliente no puede llevar NIF e identificador alternativo a la vez. Use uno solo"}</Tab>
  <Tab value="Catalan">{"El client no pot portar NIF i identificador alternatiu alhora. Useu només un"}</Tab>
</Tabs>

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

## Other errors in this category

<div className="grid grid-cols-2 gap-3 not-prose">
  <Card title="ALTERNATIVE_ID_COUNTRY_REQUIRED" description="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." href="/errors/ALTERNATIVE_ID_COUNTRY_REQUIRED" />
  <Card title="ALTERNATIVE_ID_INVALID" description="The alternative identifier is not valid" href="/errors/ALTERNATIVE_ID_INVALID" />
  <Card title="ALTERNATIVE_ID_REQUIRES_SPAIN" description="Type NOT_REGISTERED (07) is only valid for Spain; received country: '‹value›'" href="/errors/ALTERNATIVE_ID_REQUIRES_SPAIN" />
  <Card title="ALTERNATIVE_ID_SPAIN_INVALID_TYPE" description="For customers with country ES only types PASSPORT (03) or NOT_REGISTERED (07) are allowed" href="/errors/ALTERNATIVE_ID_SPAIN_INVALID_TYPE" />
  <Card title="ALTERNATIVE_ID_VAT_INVALID_FORMAT" description="'‹value›' is not a valid EU VAT number for that country: it must be the prefix '‹value›' followed by the country's VAT number, in capital letters and without spaces. If it is the recipient of an invoice already issued, correct its data with an R4 corrective invoice" href="/errors/ALTERNATIVE_ID_VAT_INVALID_FORMAT" />
</div>

## Keep exploring

<div className="grid grid-cols-2 gap-3 not-prose">
  <Card title="All Customers errors" description="Every code in this category in one table." href="/errors/category/cliente" />
  <Card title="Error reference home" description="Browse every category or jump to the handling guide." href="/errors" />
</div>

---

Full OpenAPI spec: https://docs.beel.es/api/openapi