# SERIES_UNASSIGNED_TYPE_NOT_ALLOWED

Set the series' document type. Unassigned series can no longer be created: corrective invoices need a series of their own.

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

| | |
|---|---|
| HTTP status | `422` Unprocessable Content |
| Retry | After fixing the cause |

## When it happens

The request creates a series with `document_type: UNASSIGNED`, or moves an existing series to it. `UNASSIGNED` only survives on series created before types existed.

## How to fix it

Send `STANDARD`, `SIMPLIFIED`, `CORRECTIVE` or `PROFORMA`. Corrective invoices need a `CORRECTIVE` series of their own.

## 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.

- [`POST /v1/companies/{company_id}/series`](/invoice-series/createCompanySeries)
- [`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)

## Example response

When this error occurs, the API answers `422` Unprocessable Content with a JSON body of this shape:

```json
{
  "type": "https://docs.beel.es/errors/SERIES_UNASSIGNED_TYPE_NOT_ALLOWED",
  "title": "SERIES_UNASSIGNED_TYPE_NOT_ALLOWED",
  "detail": "Set the series' document type. Unassigned series can no longer be created: corrective invoices need a series of their own.",
  "instance": "/v1/<resource>",
  "errors": [],
  "success": false,
  "error": {
    "code": "SERIES_UNASSIGNED_TYPE_NOT_ALLOWED",
    "message": "Set the series' document type. Unassigned series can no longer be created: corrective invoices need a series of their own.",
    "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">{"Set the series' document type. Unassigned series can no longer be created: corrective invoices need a series of their own."}</Tab>
  <Tab value="Spanish">{"Indica el tipo de documento de la serie. Ya no se crean series sin asignar: las rectificativas necesitan una serie propia."}</Tab>
  <Tab value="Catalan">{"Indica el tipus de document de la sèrie. Ja no es creen sèries sense assignar: les rectificatives necessiten una sèrie pròpia."}</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>

---

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