By Harry Dennis • Published: 11 Aug 2026 • 11:39 • 3 minutes readFrom October, Spain's sales calls will carry a number that cannot be rung back. Telephone operators are also required to block commercial calls made from anything else. The rule comes from a resolution signed on Tuesday April 14 by the government’s telecoms department, and published in Spain’s official state gazette, two days later. Charities, pollsters and smaller firms fall outside the ruleThe obligation follows the scope of Ley 10/2025, Spain’s customer service law, approved in December 2025. The 400 range is the final piece of that plan, following the text message register that starts blocking unregistered sender names on Tuesday September 15.