Due to recent regulatory changes promoted by the National Commission on Markets and Competition — CNMC — the sending of SMS notifications in Spain has become strictly regulated in order to combat fraud and smishing.

From 7 June 2026, telecom operators will automatically block any message that does not comply with the new sender identification requirements.

Sender Requirements and Restrictions — Alias

For your notifications to be delivered correctly to recipients, the Alias — the name that appears as the sender on the mobile phone — must comply with the following:

• Mandatory Registration: Every customised Alias must be duly registered in the CNMC public registry.
• Length: It must be between 3 and 11 characters long.
• Format: It cannot consist solely of numbers, unless it is a duly declared Spanish or international mobile number.
• Prohibited Content: The use of generic words, such as “Notice”, “Urgent”, “Appointment” or “INFO”, is not allowed. The sender must clearly identify the company or brand.

For more information, please refer to our specific FAQ section for Spain.