AEAT: Computerized Billing Systems (SIF) and VERI*FACTU
General and technical information about the Billing and VERI*FACTU Computer Systems
https://sede.agenciatributaria.gob.es/Sede/iva/sistemas-informaticos-facturacion-verifactu.html
General and technical information about the Billing and VERI*FACTU Computer Systems
https://sede.agenciatributaria.gob.es/Sede/iva/sistemas-informaticos-facturacion-verifactu.html