# VF-1255

Source: https://xmlvalid.com/rules/VF-1255

> Si FechaOperacion (FechaExpedicionFactura si no se informa FechaOperacion) es mayor o igual que 01/02/2021 no se permite el valor 'GB' para Identificaciones NIF-IVA

- Level: error
- Rule sets: VERI*FACTU checks of the AEAT Validaciones 1.2.2 (8 April 2026)
- Test: `$otype != '02' or not(starts-with($oid, 'GB')) or empty($odate) or $odate lt xs:date('2021-02-01')`

In English: For operations from 1 February 2021, an EU VAT number may not start with GB; Northern Ireland uses XI.

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