Alias Register

The Alias Register will enable the verification of names or brands appearing as senders in SMS, MMS or RCS messages sent to Spanish numbers. 

The aim is to restore users’ confidence in electronic communications via messages and to strengthen their protection against identity theft scams, an increasingly common practice in which fraudsters use aliases —for example, the name of a bank or a company— to make it appear that a message comes from a legitimate entity.

These measures form part of Order TDF/149/2025 of 12 February, which sets out various actions to combat scams involving fraudulent calls or messages.

How it works 

The Register will collect all alphanumeric identifiers (letters, numbers and letter combinations, or other characters) that can be used as the sender in messages sent to Spanish numbers. 
Aliases may be registered by alias holders (companies and public administrations) or other entities or messaging providers acting on behalf of alias holders. 

To register them, they must prove that the alias is linked to their brand, trade name, company name or domain, or other criteria, and that it complies with the technical and formatting rules set out in Circular 1/2026.

The alias holder or the applicant acting on their behalf may carry out modifications to previously registered data, as well as the suspension, reactivation and cancellation of aliases. A registered alias cannot be modified, and the qualification or disqualification of origin providers (OPs) associated with an alias may only be carried out by the alias holder, or by the origin provider (OP) concerned, subject to the holder’s prior authorisation.
Aliases may not be used until they have been effectively registered in the Alias Register. 

 

Obligations for messaging providers

Registered providers must block messages when:

• aliases not registered in the register are used,
• they originate from unregistered providers,
• they are sent without the authorisation of the alias holder, or
• they relate to foreign companies not registered in Spain, except where the recipient of the message is roaming.
  
   

Alias Registry Procedure on Electronic Headquarters