# SERIES_DOCUMENT_TYPE_LOCKED_HAS_INVOICES

The document type of a series that has already numbered invoices cannot be changed: it would number two types in the same sequence (RD 1619/2012, arts. 6.1.a and 7.1.a). Create a new series for the other type.

<Callout type="info">
**Category:** [Account settings](/errors/category/configuracion)
</Callout>

| | |
|---|---|
| HTTP status | `400` Bad Request |
| Retry | No |

## When it happens

You tried to change `document_type` on a series that has already numbered at least one invoice (`numbering_locked` is `true`). It would number two types in one sequence. An `UNASSIGNED` series can still be given a type.

## How to fix it

Create a new series of the type you need.

## Retry

Do not retry. The outcome is final: sending the same request again gets the same answer.

## Returned by

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

- [`PATCH /v1/companies/{company_id}/series/{series_id}`](/invoice-series/patchCompanySeries)

## Rules that cite this code

- [NUM-005 · Simplified invoices are numbered in their own series](/rules/numbering#num-005)
- [NUM-006 · Corrective invoices are numbered in their own series](/rules/numbering#num-006)
- [NUM-007 · A series cannot be renumbered once it has issued](/rules/numbering#num-007)

## Example response

When this error occurs, the API answers `400` Bad Request with a JSON body of this shape:

```json
{
  "type": "https://docs.beel.es/errors/SERIES_DOCUMENT_TYPE_LOCKED_HAS_INVOICES",
  "title": "SERIES_DOCUMENT_TYPE_LOCKED_HAS_INVOICES",
  "detail": "The document type of a series that has already numbered invoices cannot be changed: it would number two types in the same sequence (RD 1619/2012, arts. 6.1.a and 7.1.a). Create a new series for the other type.",
  "instance": "/v1/<resource>",
  "errors": [],
  "success": false,
  "error": {
    "code": "SERIES_DOCUMENT_TYPE_LOCKED_HAS_INVOICES",
    "message": "The document type of a series that has already numbered invoices cannot be changed: it would number two types in the same sequence (RD 1619/2012, arts. 6.1.a and 7.1.a). Create a new series for the other type.",
    "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 document type of a series that has already numbered invoices cannot be changed: it would number two types in the same sequence (RD 1619/2012, arts. 6.1.a and 7.1.a). Create a new series for the other type."}</Tab>
  <Tab value="Spanish">{"No se puede cambiar el tipo de documento de una serie que ya ha numerado facturas: numeraría dos tipos en la misma secuencia (RD 1619/2012, arts. 6.1.a y 7.1.a). Crea una serie nueva para el otro tipo."}</Tab>
  <Tab value="Catalan">{"No es pot canviar el tipus de document d'una sèrie que ja ha numerat factures: numeraria dos tipus en la mateixa seqüència (RD 1619/2012, arts. 6.1.a i 7.1.a). Crea una sèrie nova per a l'altre tipus."}</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="ACTIVE_CANNOT_DELETE" description="Cannot delete an active series. Deactivate it first" href="/errors/ACTIVE_CANNOT_DELETE" />
  <Card title="DEFAULT_CANNOT_BE_UNMARKED" description="Cannot unmark the default series. Set another series as default first" href="/errors/DEFAULT_CANNOT_BE_UNMARKED" />
  <Card title="DEFAULT_CANNOT_DEACTIVATE" description="Cannot deactivate the default series. Set another series as default first" href="/errors/DEFAULT_CANNOT_DEACTIVATE" />
  <Card title="DEFAULT_CANNOT_DELETE" description="Cannot delete the default series. Set another series as default first" href="/errors/DEFAULT_CANNOT_DELETE" />
  <Card title="ENTITY_TYPE_INCONSISTENT_WITH_NIF" description="The entity type ‹value› does not match the NIF ‹value›: an individual is identified by a DNI or NIE, and a company or entity by a NIF that starts with a legal-form letter" href="/errors/ENTITY_TYPE_INCONSISTENT_WITH_NIF" />
</div>

## Keep exploring

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

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