From 17 October 2026, all commercial telephone calls in Spain must come from a nine-digit number beginning with 400, with operators blocking those that fail to comply.
The new prefix will allow people to recognise sales and marketing calls before answering. Telephone operators will be required to block commercial calls made from mobile, geographical, 800 or 900 numbers.
Numbers beginning with 400 will be one-way. Companies will be able to call customers, but recipients will not be able to return a missed call. This is intended to reduce fraud involving people calling unfamiliar numbers.
Customers may also be able to ask their telephone provider to block all calls from the 400 range. Anyone who receives a commercial call from another type of number will be able to report it to the Telecommunications User Service Office or the CNMC, Spain’s competition and markets regulator.
However, the new prefix does not give companies permission to call anyone they choose. Businesses must still follow Spain’s data-protection and marketing rules. They must have consent or another valid legal reason for making the call and must stop contacting anyone who objects.
Customer-service calls will follow different rules. They may continue to come from approved short numbers, free 800 and 900 numbers or geographical landline numbers. Ordinary mobile numbers cannot be used.
The measure is part of the Spanish Government’s campaign against telephone and text-message fraud. Since the anti-scam programme began in March 2025, operators have blocked more than 192 million suspicious calls and 17 million fraudulent text messages.
Spain is also creating an official database of the names and codes used by companies and public bodies when sending text messages. Operators will block messages using unregistered identities, helping prevent criminals from pretending to be banks, businesses or government organisations.
