As of September 15, 2026, operators will block all SMS from senders not registered in the CNMC alias registry. At Acumbamail we are Registered Origin Provider (PRO) and we will process the registration of your aliases for you.
Legal framework: Order TDF/149/2025 · Circular 1/2026 of the CNMC · Affects SMS, MMS, and RCS
Enter the sender you use in your SMS and we will check if it complies with the format rules of Circular 1/2026.
This check is indicative and only covers the format. It does not consult the CNMC Registry: it cannot know if another holder has already registered that alias, if the term is considered generic, or if your accreditation will be accepted.
Verification codes, order confirmations, and delivery notices are the first to fail: they are the messages that depend most on the alphanumeric sender.
This is what the operator shows when the recipient is roaming and the alias is not listed in the Registry.
The regulation applies to all messages sent to a Spanish number, regardless of the country of origin. International traffic is the one accumulating the most blocks.
Registering the alias is only half of the process. If you have not enabled your sending provider, the block remains.
The alias registry is the official database where alphanumeric senders used in SMS, MMS, and RCS sent to Spanish numbers must be registered. It was created to cut smishing: until now, anyone could sign a message as a bank or a courier company.
1. The alias must be registered in the CNMC Registry and linked to its legitimate holder, accredited by a registered trademark (OEPM or EUIPO), corporate name, or ownership of a related domain.
2. The provider sending the message must be enabled as a Registered Origin Provider (PRO) for that specific alias.
If either of the two is missing, the operator blocks the message. And non-compliance can lead to penalties under the General Telecommunications Law.
We are a Registered Origin Provider with the CNMC. We can act as an authorized third party and take care of the entire process.
We review all the senders you use, tell you which ones comply with the format, which ones you need to change, and what documentation you can use to accredit each one.
We submit the application to the CNMC's Electronic Headquarters on your behalf, with several aliases in the same file if necessary. If you are already sending with us, we do the grouped upload of all your active senders.
We remain linked as an enabled provider for your aliases, synchronize with the official database, and notify you of any status changes before it becomes a block.
The ordinary validation period of the CNMC is one month from the application, so the sooner it is submitted, the sooner delivery is recovered.
Tell us what senders you use and we will tell you what situation you are in and what needs to be done. We will respond in less than 24 business hours.
Yes. The Registry is still open at the CNMC's Electronic Headquarters and you can register your aliases at any time. The difference is that now your messages are already being blocked while the registration is not validated and you have not enabled your provider.
For a message to be delivered, two conditions must be met at the same time: that the alias is registered and linked to its legitimate holder, and that the provider sending the message is enabled as a Registered Origin Provider (PRO) for that specific alias. If the second is missing, operators will block the message anyway.
There is no limit, as long as each alias meets the format criteria and you can prove a legitimate link with each one. Additionally, you can include multiple aliases in the same registration request.
Yes. The regulation applies to all messages directed to Spanish numbers, regardless of their geographical origin. If the recipient is roaming, the operator replaces the alias with the mention "NOT VALIDATED".
Yes. Circular 1/2026 expressly includes RCS messages, in addition to traditional SMS and MMS.
If your alias meets the format requirements and you can prove the legitimate link, you can continue using it once registered. You will only have to change it if it contains prohibited characters, exceeds 11 characters, or is a generic term rejected by the CNMC.
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