Spain implements 400 prefix to identify telemarketing calls

Starting October 17, Spain will implement a new regulatory system to identify commercial telemarketing calls using the 400 prefix. This nine-digit numbering range is reserved exclusively for outbound sales and promotional calls, allowing consumers to distinguish commercial offers from service-related communications such as billing or incident reports.

Under the new rules, companies using any other numbering for sales calls could face significant penalties, with fines reaching up to one million euros. Telecommunications operators, including Movistar, Vodafone, Orange, and MasOrange, are responsible for technical implementation and must enable the range within their networks.

While the prefix acts as a visual identifier, it does not automatically block calls. However, consumers gain new rights: they cannot call back numbers starting with 400, and they may request their operators to block the entire 400 range to avoid commercial offers entirely. The measure aims to provide greater transparency and facilitate consumer complaints regarding unauthorized commercial contact.