# VF-1245

Source: https://xmlvalid.com/rules/VF-1245

> Si el campo Impuesto está vacío o tiene valor IVA(01) o IPSI(02) o IGIC(03) el campo ClaveRegimen debe de estar cumplimentado.

- Level: error
- Rule sets: VERI*FACTU checks of the AEAT Validaciones 1.2.2 (8 April 2026)
- Context: `/*:RegFactuSistemaFacturacion/*:RegistroFactura/*:RegistroAlta/*:Desglose/*:DetalleDesglose`
- Test: `not($vatlike) or $key != ''`

In English: ClaveRegimen (the VAT regime) is required when the tax is VAT (01), IGIC (03) or left out.

## Why it fails

- Software that sends only CalificacionOperacion: the regime key is a field of its own, 01 for the general regime.

## How to fix it

- Give ClaveRegimen on every DetalleDesglose, 01 unless a special regime applies.

Validate a document against these rules: https://xmlvalid.com/validate