# REGIME_KEY_CLASSIFICATION_NOT_ACCEPTED

Regime key ‹value› does not accept a line with exemption_reason ‹value›: with that key AEAT only accepts exemption_reason ‹value›

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

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

## When it happens

The line's `exemption_reason` (or its absence) is not one AEAT accepts with its regime key: `04` needs reverse charge or an exemption; `08` only `NO_SUJETA_LOCALIZACION` at 0 %; `10` only `NO_SUJETA_ART_7_9`; `11` no reverse charge; `07` no reverse charge, no not-subject reason and only `EXENTA_ART_20` or `OTRO` as exemptions.

## How to fix it

Change the regime key or the `exemption_reason` of the line so the pair is one AEAT accepts.

## 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}/invoices`](/invoices/createCompanyInvoice)
- [`PATCH /v1/companies/{company_id}/invoices/{invoice_id}`](/invoices/patchCompanyInvoice)
- [`POST /v1/companies/{company_id}/invoices/{invoice_id}/issue`](/invoices/issueCompanyInvoice)

## Rules that cite this code

- [TAX-015 · Regime key 08 means not subject to the line's tax](/rules/taxes#tax-015)
- [TAX-017 · Special regime keys carry the classification AEAT requires](/rules/taxes#tax-017)

## 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/REGIME_KEY_CLASSIFICATION_NOT_ACCEPTED",
  "title": "REGIME_KEY_CLASSIFICATION_NOT_ACCEPTED",
  "detail": "Regime key ‹value› does not accept a line with exemption_reason ‹value›: with that key AEAT only accepts exemption_reason ‹value›",
  "instance": "/v1/<resource>",
  "errors": [],
  "success": false,
  "error": {
    "code": "REGIME_KEY_CLASSIFICATION_NOT_ACCEPTED",
    "message": "Regime key ‹value› does not accept a line with exemption_reason ‹value›: with that key AEAT only accepts exemption_reason ‹value›",
    "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">{"Regime key ‹value› does not accept a line with exemption_reason ‹value›: with that key AEAT only accepts exemption_reason ‹value›"}</Tab>
  <Tab value="Spanish">{"La clave de régimen ‹value› no admite una línea con exemption_reason ‹value›: con esa clave la AEAT solo acepta exemption_reason ‹value›"}</Tab>
  <Tab value="Catalan">{"La clau de règim ‹value› no admet una línia amb exemption_reason ‹value›: amb aquesta clau l'AEAT només accepta exemption_reason ‹value›"}</Tab>
</Tabs>

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

> Placeholders like `‹value›` are filled in at runtime with the actual values of your request.

## Other errors in this category

<div className="grid grid-cols-2 gap-3 not-prose">
  <Card title="ATTACH_SOURCE_INVOICE_UNAVAILABLE" description="A source invoice is not available (it does not exist or you no longer have access); uncheck the source invoices attachment to send without the folder" href="/errors/ATTACH_SOURCE_INVOICE_UNAVAILABLE" />
  <Card title="ATTACH_SOURCE_INVOICES_NO_SOURCES" description="The invoice has no consolidation disbursements: there are no source invoices to attach" href="/errors/ATTACH_SOURCE_INVOICES_NO_SOURCES" />
  <Card title="ATTACH_SOURCE_INVOICES_REQUIRES_PDF" description="Attaching the source invoices also requires attaching the invoice PDF" href="/errors/ATTACH_SOURCE_INVOICES_REQUIRES_PDF" />
  <Card title="ATTACH_SOURCE_PDF_MISSING" description="These source invoices have no generated PDF: ‹value›" href="/errors/ATTACH_SOURCE_PDF_MISSING" />
  <Card title="ATTACH_SOURCE_ZIP_TOO_LARGE" description="The source invoices ZIP (‹value› MB) exceeds the maximum sendable size (‹value› MB)" href="/errors/ATTACH_SOURCE_ZIP_TOO_LARGE" />
</div>

## Keep exploring

<div className="grid grid-cols-2 gap-3 not-prose">
  <Card title="All Invoices errors" description="Every code in this category in one table." href="/errors/category/invoicing" />
  <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