# VF-1188

Source: https://xmlvalid.com/rules/VF-1188

> El NIF del bloque Tercero debe ser diferente al NIF del ObligadoEmision.

- Level: error
- Rule sets: VERI*FACTU checks of the AEAT Validaciones 1.2.2 (8 April 2026)
- Context: `/*:RegFactuSistemaFacturacion/*:RegistroFactura/*:RegistroAlta`
- Test: `not(*:Tercero/*:NIF) or normalize-space(*:Tercero/*:NIF) != normalize-space(*:IDFactura/*:IDEmisorFactura)`

In English: The third party's NIF (Tercero) must differ from the issuer's.

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