If you send text messages to customers in Spain from your company name, they now need to be registered. Since 15 September 2026, Spanish mobile networks block SMS, MMS and RCS messages to +34 numbers from any alphanumeric sender ID that isn’t on the national Alias Registry run by the CNMC, Spain’s markets and competition regulator. This guide explains what changed, who it affects, how to register, and what to do if your registration isn’t ready yet.
In short: register each sender name you use for Spain with the CNMC Alias Registry, naming your messaging provider, then tell your provider so your traffic is allowed through. Until it’s active, messages to Spain from that name are blocked. Sending from a Spanish phone number isn’t covered by the registry, so it’s a useful stop-gap.
What changed in Spain
Spain has introduced the registry to fight smishing: scam texts that pretend to come from banks, delivery firms and government services. Every alphanumeric sender ID, and every RCS agent name, used to message Spanish numbers must now be registered to the organisation entitled to use it, together with the provider that delivers its messages. Networks then block anything that doesn’t match.
| Date | What happened |
|---|---|
| 12 February 2025 | Order TDF/149/2025 sets out the requirement to register sender IDs |
| 27 March 2026 | CNMC Circular 1/2026 published, setting out how the Alias Registry works |
| 7 June 2026 | The CNMC Alias Registry opens for registrations |
| 15 September 2026 | Spanish networks start blocking messages from unregistered sender IDs |
Who it affects
- Anyone sending to +34 numbers from a name, such as
BrightShop, wherever the company is based. A UK business texting customers in Spain is covered. - SMS, MMS and RCS. RCS agent names are included, not just SMS sender IDs.
- Not numeric senders. Messages sent from a phone number aren’t part of the alias registry.
- Resellers and integrators too. If you send on behalf of your own customers, you’re recorded as a third party on their registration.
Sender ID rules in Spain
- 3 to 11 characters. Letters (including ñ and ç), digits and spaces.
- A legitimate link to the name. For example a registered trademark, your company name, an internet domain you own, or a merchant registration.
- One owner, named providers. The alias is registered to its owner, and only the providers listed on the registration can deliver messages from it.
Generic names such as Info or Verify are a poor choice in any country. See our guide to UK SMS sender ID rules for why your brand name works better.
How to register your sender ID
The fastest route is usually to register directly through the CNMC’s online office. You’ll need:
- A way to sign in. A digital certificate recognised in Spain, or the Cl@ve system. Companies outside Spain often use a Spanish representative who holds one.
- The alias owner’s details. Company name, tax ID (NIF), full address, and a representative with power of attorney or legal representation. The representative can be the owner, an employee or another company.
- The alias and its link. Each sender name, and evidence of your right to use it, such as a trademark, company or domain registration.
- Your messaging provider’s details. The provider that delivers your Spanish traffic. Ask us and we’ll give you the exact details to enter.
- Any third party. If a partner or reseller sends on your behalf, their company name, tax ID and representative too.
Approval can take up to a month. You can register several aliases in one application, and if someone files on your behalf, you’ll need to confirm it within 10 working days.
Once your alias is active
When your sender ID shows as active in the CNMC Alias Registry, let us know with the tax ID (NIF) you registered under. We use it to match your account to the registry so your messages to Spain are allowed through. The details must match your registration exactly.
If your registration isn’t ready
Registration can take time, and some companies have found the CNMC portal difficult to access from outside Spain. To keep messages flowing in the meantime:
- Send from a number. Numeric senders aren’t covered by the alias registry. We can arrange a Spanish number for your Spanish traffic, which also lets customers reply.
- Check where you send to Spain. Look for any campaigns, reminders or one-time passcodes that go to +34 numbers from a name, including ones sent by your systems through our API.
- Keep going with registration. A number is a temporary safeguard. Registering protects your brand name for the long term, and stops anyone else using it.
Frequently asked questions
Do I need to register my SMS sender ID to send to Spain?
Yes, if you send from a name. Since 15 September 2026, Spanish mobile networks block SMS, MMS and RCS messages to +34 numbers from alphanumeric sender IDs that aren’t registered with the CNMC Alias Registry and linked to your messaging provider.
Does this apply to UK companies?
Yes. Registration is required wherever the sender is based. What matters is that the message goes to a Spanish (+34) mobile number.
Are numeric senders affected?
No. The registry covers alphanumeric sender IDs and RCS agent names. Messages sent from a phone number aren’t part of it, so a Spanish number is a practical stop-gap while registration is completed.
What can my sender ID contain?
Between 3 and 11 characters: letters (including ñ and ç), digits and spaces. You also need to show a legitimate link to the name, such as a trademark, company name or internet domain.
How long does registration take?
The CNMC can take up to a month to approve an application. Several aliases can go in one application. If a third party files for you, you confirm the request within 10 working days.
What happens if my sender ID isn’t registered?
Messages to Spanish numbers from that name are blocked by the networks. They aren’t delivered, so any SMS to Spain from an unregistered name is wasted.
Sending to Spain?
We’ll help you check which of your messages go to Spain, give you the provider details for your CNMC registration, and arrange a Spanish number while it’s approved.