# Spain commercial call regulation and spam prevention > Live situation record from CLSTR: https://clstr.news/situations/spain-commercial-call-regulation-and-spam-prevention > Updated: 2026-08-11T09:39:16.000Z. Sources: 2. Developments: 2. A study by the Organización de Consumidores y Usuarios (OCU) revealed that 98% of Spanish consumers continue to receive unsolicited commercial calls, despite existing regulations like the 2023 amendment to the General Telecommunications Law. The report noted that the implementation of a mandatory 400 prefix to identify commercial calls had been delayed, with many companies still using ordinary numbers and existing consent requirements being bypassed by pre-checked boxes. To address these issues and combat fraud, Spain is set to mandate that all commercial telephone calls originate from a nine-digit national number beginning with the 400 prefix starting October 17, 2026. These numbers will be outgoing only, and operators will block incoming traffic to this range to prevent recipients from calling back potentially fraudulent lines. Furthermore, operators will be required to block commercial calls made from non-compliant mobile, geographic, 800, or 900 numbers. Consumers may also be given the option to block the entire 400 range to silence all commercial calls. ## Timeline ### 2026-08-11: Spain to mandate 400 prefix for commercial calls to combat fraud Spain will mandate that all commercial calls use a specific 400 prefix starting October 2026, allowing users to identify sales calls and enabling operators to block them or the entire range. 2 sources. https://clstr.news/cluster/spain-to-mandate-400-prefix-for-commercial-calls-to-combat-fraud ### 2026-07-30: Spain's consumers hit 98% spam call rate despite new 400‑prefix law OCU reports 98 % of Spaniards still receive spam calls in 2026, citing the stalled rollout of the 400‑prefix law and limited blocking by operators and Apple. 4 sources. https://clstr.news/cluster/spains-consumers-hit-98-spam-call-rate-despite-new-400prefix-law --- Cite as: Spain commercial call regulation and spam prevention. CLSTR, https://clstr.news/situations/spain-commercial-call-regulation-and-spam-prevention