Spain’s New Sender ID Registry: What You Need to Know for 2026

To fight SMS phishing (smishing) and boost security, the Spanish National Markets and Competition Commission (CNMC) has introduced new regulations (Order TDF/149/2025).

Starting June 7, 2026, you can no longer send business SMS in Spain using an unverified “Alias” (Sender ID). Any message using an unregistered name or sent through an unauthorized provider will be automatically blocked by Spanish carriers.

To continue sending to Spanish recipients using a sender ID, you must register your Sender ID as soon as possible and we can help with this.

Requirements for “Legitimate Link”

To register an Alias, you must prove you have the right to use it and that it identifies your brand. You’ll need one of the following to evidence this:

  • Trademark/Trade Name: A registration certificate.
  • Corporate Name: Deed of incorporation or Commercial Registry certificate.
  • Web Domain: Proof of ownership.

We will also need a signed declaration from you confirming all information provided is true and accurate.

Technical Rules for Your Alias

The CNMC has strict formatting rules. If your Alias doesn’t fit these, it will be rejected:

Feature Requirement
Length 3 to 11 characters.
Allowed Characters Letters (a-z, A-Z, including ñ and ç) and numbers (0-9).
Special Characters @, &, ., –, _, + and spaces (not at the start/end).
Prohibited Accents (á, é, etc.), symbols like !, ?, #, %, *, €, or brackets.
Naming Policy No generic names (e.g., “Message”, “Bank”). No numeric-only IDs.

Registration Process

In order for us to register your Sender ID for you, we will need to collect documentation to confirm the identity of your business and a legal representative of your business. The legal representative must either be listed on the Commercial Registry (e.g as a director) or have a Power of Attorney. 

We will also require a signed letter of authority to grant us authority to complete the registration on your behalf.

International Traffic

If your company is based outside Spain but sends messages to Spanish numbers (+34), you must use an authorized local provider like Esendex. International routes that aren’t authorised by the regulator will be blocked.

FAQ

Does this apply to RCS? Yes. The rules are identical for SMS, MMS, and RCS to ensure total channel security but not other channels like Whatsapp.

Is the registration permanent? Sender IDs can be registered for an indefinite period but if an Alias is inactive for 12 consecutive months, the CNMC may cancel it.

Can I use my own name? Only if you can prove a legitimate professional link and it doesn’t cause confusion with established brands or government bodies.

Next Steps

  1. Audit your IDs: List every Sender ID you currently use and review them against the above rules.
  2. Gather Proof: Collect evidence of the legitimate link to your Sender ID and business identity. 
  3. Check your Inbox: If you’re a customer, look out for our specific registration instructions but if you want to reach out you can always contact us on our support number.