Key data
| Regulation | Circular 3/2026, of September 8, from CNMC — modifies Circular 1/2026, of March 18, which regulates the Alias Registry |
|---|---|
| Publication | September 12, 2026 |
| Entry into force | September 12, 2026 |
| Critical blocking date | September 15, 2026 |
| Deadline for pre-registration request | Before 15:00 h on September 14, 2026 |
| Maximum duration of provisional enablement | Three months from pre-registration, or until prior express resolution |
| Affected parties | Companies, Public Administrations and SMS/MMS/RCS messaging providers with aliases pending validation |
| Category | Electronic Communications / Telecommunications |
| Year | 2026 |
If your company sends transactional SMS—order confirmations, bank alerts, appointment notifications, OTPs—using an identifier alias (the name that appears instead of the phone number), September 15, 2026 was the date when the blocking obligations of the CNMC Alias Registry came into full effect.
The problem: the massive volume of pending validation requests threatened to abruptly cut off communications from thousands of companies and Public Administrations. To avoid this scenario, Circular 3/2026 introduces a transitional pre-registration measure that keeps aliases operational while the validation process is completed.
What does this regulation establish?
Circular 1/2026, of March 18, created the Alias Registry: a system by which companies and Public Administrations must register and validate the alphanumeric aliases they use as sender in SMS, MMS and RCS messages. Without valid registration, the alias is blocked and messages do not reach the recipient.
Circular 3/2026 modifies that rule to introduce a safety valve against the avalanche of pending requests. The following table summarizes the specific changes:
| Aspect | Circular 1/2026 (before) | Circular 3/2026 (after) |
|---|---|---|
| Status of alias pending validation | Blocked from 15/09/2026 | Provisionally enabled if requested before 15:00 h on 14/09/2026 and meets format requirements |
| Duration of provisional enablement | Did not exist | Until the holder authorizes the alias or CNMC resolves expressly, with a maximum of three months |
| Exemption from regulatory requirements | Not applicable | No: pre-registration does not exempt from completing pending validation procedures |
The measure is strictly transitional. It does not constitute a general exemption nor eliminates the obligation to complete the registration process. The alias remains in processing and must be authorized by the holder or resolved by CNMC within three months.
Economic and operational impact
The most immediate impact is not a direct fine: it is operational interruption. A blocked alias means that SMS sent with that sender do not arrive. For companies that depend on critical transactional communications—banks, insurers, e-commerce, private healthcare, Public Administration—this equals:
- Customers who do not receive OTPs (one-time passwords) and cannot complete operations.
- Security or fraud alerts that do not arrive.
- Appointment, delivery or order status notifications lost.
- Reputational damage and increased customer service calls.
Provisional pre-registration eliminates that risk of interruption for a maximum of three months, providing time to complete validation without extreme urgency. However, companies that did not request their alias before 15:00 h on September 14 do not benefit from this measure and must manage their situation urgently.
Who does it affect?
- Private companies that send SMS, MMS or RCS with alphanumeric identifier alias (brand name as sender).
- Public Administrations that use messaging with aliases for citizen notifications.
- SMS/MMS/RCS messaging service providers that manage aliases on behalf of their clients.
- Any entity with alias pending validation in the CNMC Alias Registry as of September 14, 2026.
Sectors with greatest exposure: banking and insurance, healthcare, e-commerce and logistics, telecommunications, Public Administration and digital authentication services.
Practical example
A banking entity uses the alias "MyBank" as the sender of its authentication SMS (OTP). It requested registration in the Alias Registry before September 14 at 14:45 h and the alias meets the format requirements set by Circular 1/2026.
Thanks to the provisional pre-registration of Circular 3/2026, the alias "MyBank" remains operational from September 15, while CNMC processes the validation. The bank has up to three months—or until CNMC resolves earlier—to complete the process. During this period, its customers continue to receive authentication SMS normally.
If the entity had not requested the alias before 15:00 h on September 14, the alias would have been blocked on September 15 and no SMS sent with that sender would have reached its customers.
What should companies do now?
- Verify if the alias was requested before 15:00 h on September 14, 2026. Only aliases requested before that time and that meet format requirements benefit from provisional pre-registration.
- Check the status of the request in the CNMC Alias Registry. Provisional enablement is not automatic without having initiated the procedure.
- Complete pending validation procedures urgently. Pre-registration does not exempt from regulatory requirements: the alias must be authorized by the holder or resolved by CNMC within a maximum of three months.
- If the alias was not requested in time, contact the messaging provider and CNMC to explore regularization options, as the alias will be blocked from September 15.
- Review all active aliases (SMS, MMS and RCS) to ensure that none are left out of the registry once the provisional period expires.
Frequently asked questions
What is the CNMC provisional pre-registration of SMS aliases?
It is a transitional measure introduced by Circular 3/2026 that provisionally enables SMS, MMS or RCS aliases requested before 15:00 h on September 14, 2026 and that meet format requirements. It allows those aliases to remain operational while CNMC processes their validation, preventing mass blocks from September 15, 2026.
How long does the provisional enablement of a pre-registered alias last?
Provisional enablement is maintained until the holder authorizes the alias or CNMC resolves expressly, with a maximum period of three months from pre-registration. After that period without resolution, the alias would lose its provisional enablement.
Does pre-registration exempt from completing alias registration?
No. Circular 3/2026 is explicit: provisional pre-registration does not constitute exemption from regulatory requirements nor general exemption from pending procedures. The company must complete the validation process within three months.
What happens if my company did not request the alias before 15:00 h on September 14?
The alias does not benefit from provisional pre-registration and is blocked from September 15, 2026, in accordance with the obligations of Circular 1/2026. Messages sent with that alias will not reach recipients. It is necessary to manage the situation urgently with CNMC and the messaging provider.
What types of messaging are affected by the Alias Registry?
The Alias Registry regulated by Circular 1/2026 and modified by Circular 3/2026 affects identifier aliases used in SMS, MMS and RCS messaging. Companies, Public Administrations and messaging service providers operating with these channels are required to register their aliases.
Official source
Consult complete regulation in official source
Notice: This article is for informational purposes only and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-19053
