Spain has postponed the implementation of the Verifactu Ordinance to 2027, extending the original July 2025 deadline. An extraordinary opt‑out window for voluntary SII participants runs from 26 December 2025 to 31 January 2026, allowing withdrawal via Form 036/037 effective 1 January 2026. The decree also clarifies that mandatory SII participants cannot opt out and that non‑compliant invoicing software cannot be sold after 29 July 2025.