Spain's Tribunal Supremo (the Supreme Court) handed down judgment STS 620/2026 on Thursday 21 May, annulling the mandatory national registration number created by Royal Decree 1312/20241. The court kept the data pipes alive. The digital single window known as the SDEP (the portal through which short-let platforms transmit listing data to authorities) and the transmission duties both stand, yet the one number a host needed to list legally is gone. For anyone renting out a flat in Spain, the national licence they were chasing no longer exists, and authority over registration reverts to their region.
The ruling turned on competence, not housing policy. Spain's seventeen autonomous communities already run their own short-term-rental (STR) registries, and the court found the central state lacked the constitutional power to overlay a national one on top of them2. The appellant was the Generalitat Valenciana, the Valencian Regional Government, which in the same fortnight built Spain's tightest local STR rule, a 2% cap on tourist lets in pressured zones. Valencia killed the national layer it could not control and kept the local one it could.
Two consequences follow. Madrid's consumer-affairs ministry fined Airbnb €64 million in December 2025 for unlicensed listings and falsified registration numbers, the largest STR enforcement action in EU history. The High Court of Justice of Madrid declined in March to suspend that fine and has set no hearing date on Airbnb's reconsideration motion. The registration instrument those numbers came from is now partly void, so Airbnb's lawyers gain an argument they did not hold a month ago, and a platform watcher should expect the fine contested for months rather than paid. The counter is narrow but real: the ministry has always framed the penalty as concerning the accuracy of what Airbnb listed, not the registry's constitutional basis, and the Supreme Court did not touch the fine itself.
The second consequence runs through Brussels. EU Regulation 2024/1028, the bloc-wide short-let registration regime, reached full application on 20 May, yet Spain now enforces it through a patchwork of seventeen regional registries rather than the single one the rule envisaged. The European Commission has issued no readiness assessment and no infringement notice since day one. A host comparing Spanish regions can no longer assume one national rule; what they must register for now depends on the comunidad they let in.
