CNMC pre-registers SMS aliases to avoid the September block

The National Commission on Markets and Competition (CNMC) has approved Circular 3/2026, of September 8, which provides for the transitional pre-registration of messaging aliases for which registration was requested before 3:00 PM on September 14, 2026. The measure seeks to avoid the interruption of SMS/MMS/RCS messaging services when, on September 15, the blocking of aliases not registered in the Alias Registry comes into effect. The regulation is published in the Official State Gazette (BOE) number 226, of September 12, 2026, with reference BOE-A-2026-19053.

The circular develops Order TDF/149/2025, of February 12, which establishes measures to combat identity theft scams through fraudulent calls and text messages. Articles 8.1 and 8.2 impose an obligation on companies and public administrations to previously register their aliases in the Alias Registry, managed by the CNMC, indicating the messaging providers authorized for their transmission. Starting September 15, 2026, operators must block messages identified by aliases that are not listed in the registry or that have not been received from authorized providers.

A registry saturated by requests

The Alias Registry was regulated by Circular 1/2026, of March 18, in effect since March 28, and was modified by Circular 2/2026, of June 5, in effect since June 10. Since April, and with the June changes, alias holders, registered providers, and authorized representatives can request registration through the web form of the CNMC’s electronic office, and registered origin providers (PRO) can do so via bulk upload.

In the first months of operation, thousands of requests were submitted, and in the weeks leading up to September 15, the volume has skyrocketed. The CNMC acknowledges a high number of delays or lack of response to electronic communications sent to holders, meaning many aliases remain pending final validation.

Transitional pre-registration

Given the material impossibility of resolving all requests before September 15, the Plenary of the CNMC Council, in its session on September 8, agreed to transitionally pre-register aliases requested before 3:00 PM on September 14 that meet the format requirements of Annex III of Circular 1/2026 and are pending processing. The pre-registration will remain in effect until the authorization period by the holder expires or until the CNMC resolves the registration or denial, within a maximum period of three months.

The measure is strictly temporary and limited, and does not constitute a general waiver of the remaining procedures nor an exemption from regulatory requirements. To qualify for it, applications must comply with:

• The basic format requirements of Annex III of Circular 1/2026.
• The responsible declaration regarding the linking of aliases with the established criteria (Annex V).
• In the case of PROs, the responsible declaration of compliance with the applicable framework (Annex II).

Impact for companies and users

The measure protects operational services and processes of an essential or critical nature and transactional communications whose interruption could cause harm to users, companies, or Public Administrations. The CNMC justifies the decision based on a balancing of conflicting interests, to ensure an orderly transition to the new regime and preserve the continuity of communications between companies and their customers.

The circular, signed by the president of the CNMC, Juan José Ganuza Fernández, will enter into force on the day following its publication in the BOE. With this, the regulator prevents the automatic blocking of aliases pending administrative validation from interrupting legitimate messaging services right as the new security obligations come into effect.

Source: Official State Gazette (BOE), no. 226, Saturday, September 12, 2026, Sec. I, page 121645 (official reference: BOE-A-2026-19053).