How can we help?

Before You Begin

Before starting the registration process, gather the following information.

Sender ID Information

• The alphanumeric Sender ID (alias) to register.
• The relationship between the Sender ID and the organization (for example, your company name, brand, or trademark).

Organization Information

• Organization legal name.
• Tax identification number.
• Registered business information.
• Contact information.
• Legal representative information.

Supporting Documentation

Organizations may be asked to provide documentation demonstrating the right to use the requested Sender ID, such as:

• Registered trademark.
• Registered business name.
• Internet domain corresponding to the requested Sender ID.
• Any additional documentation requested during the registration process.

Registering Directly with the CNMC

Organizations with a valid Spanish digital certificate or a qualified EU eIDAS (electronic Identification, Authentication and trust Services) digital certificate can register their Sender ID directly through the CNMC Alias Registry.

Accessing the CNMC Alias Registry

Sign in to the CNMC Alias Registry using your digital certificate.

Organizations that cannot authenticate using a Spanish or qualified EU eIDAS digital certificate register through an authorized representative. This registration method is covered later in this guide.

Completing the Registration Form

Complete the registration form with:

• Organization details.
• Legal representative information.
• The alphanumeric Sender ID to register.
• Any additional information requested by the CNMC.

Review all information carefully before submitting the application.

Selecting a Provider

When completing the registration form, select:

• Provider (PRO): Twilio Ireland Limited
• Third Party (Tercero): TCS LLC

These selections associate the registered Sender ID with the messaging infrastructure used by Talkdesk.

Approving the Registration

After submitting the registration request, the CNMC notifies the legal representative identified in the application.

The legal representative must authenticate using their digital certificate and approve the registration within the timeframe specified by the CNMC.

If the authorization is not completed within the required period, the registration request may expire and need to be submitted again.

Submitting the Registration Confirmation to Talkdesk

After the Sender ID registration has been approved by the CNMC, submit the registration confirmation to the Talkdesk Customer Care team.

Include:

• The registered alphanumeric Sender ID.
• The CNMC registration confirmation or proof of registration.
• The Talkdesk account where the Sender ID should be provisioned.
• Any additional Talkdesk accounts that should use the same Sender ID (if applicable).

Once received, Talkdesk will validate the information and submit the provisioning request to the underlying messaging provider.

Sender ID Provisioning

The Sender ID is provisioned for use with Talkdesk Messaging once:

• The CNMC registration is approved.
• The provisioning request is approved by the underlying messaging provider.

If the provisioning request is approved before the CNMC registration is finalized, provisioning will remain pending until the regulatory approval is completed.

Registering Through Talkdesk (Authorized Representative)

Organizations that cannot register directly with the CNMC - for example, because they do not have a valid Spanish or qualified EU eIDAS digital certificate - can register a Sender ID through Talkdesk.

In this registration method, Talkdesk acts as the point of contact and submits the registration request to the underlying messaging provider, which acts as the authorized representative before the CNMC.

Confirming Eligibility

This registration method is intended for organizations that are registered outside of Spain.

Gathering the Required Documentation

Before submitting your request, prepare the following documentation:

Proof of Business: A business registration document showing the organization's:

• Legal name.
• Registered address.
• Business registration number.
• Company officers or legal representatives (where applicable).

Proof of Legal Representative

A government-issued identification document for the legal representative identified in the business registration documents.

CNMC Letter of Authorization (LOA)

The CNMC Letter of Authorization (LOA) must be completed and signed by the legal representative of the organization requesting the Sender ID.

Proof of Sender ID Ownership

Documentation demonstrating your right to use the requested Sender ID if it does not exactly match your organization's legal name.

Examples include:

• Registered trademark.
• Registered business name.
• Internet domain associated with the Sender ID.
• Other supporting documentation demonstrating ownership or authorization.

Submitting Your Registration Request

Once all required documentation is gathered, submit a request to the Talkdesk Customer Care team. 

Include:

• The requested alphanumeric Sender ID.
• Your Talkdesk account name.
• All required supporting documentation listed above.

Registration Review

After the request is submitted:

1. Talkdesk reviews the information provided to confirm that the request is complete.
2. The underlying messaging provider reviews the documentation before submitting the registration to the CNMC.
3. The CNMC reviews the registration request and determines whether the Sender ID can be registered.

If additional information or documentation is required during the review process, Talkdesk will contact you.

Sender ID Provisioning

Once the registration has been approved by the CNMC and the Sender ID has been provisioned by the underlying messaging provider, the Sender ID will be available for use with Talkdesk Messaging.

Frequently Asked Questions

Do I need to register each Sender ID separately?

Yes. Each unique alphanumeric Sender ID (alias) must be registered separately with the CNMC.

Sender IDs are case-sensitive.

What happens if I do not register before 15 September 2026?

Beginning 15 September 2026, Spanish mobile network operators are required to block SMS, MMS, and RCS messages sent using unregistered alphanumeric Sender IDs.

Can I continue sending messages while my registration is being reviewed?

Before 15 September 2026, messages may continue to be delivered while your registration is being processed.

After the enforcement date, only registered Sender IDs will be accepted by participating mobile network operators.

How much does Sender ID registration cost?

Registration with the CNMC is free. There is no charge from the CNMC to register or maintain an alphanumeric Sender ID.

What happens if my registration is rejected?

If you registered directly with the CNMC, the CNMC will notify you of the reason for the rejection and provide an opportunity to correct the application, subject to its registration procedures.

If you registered through Talkdesk, Talkdesk Customer Care will contact you if additional information is required during the registration process.

I do not have a Spanish digital certificate. What are my options?

Organizations that cannot register directly with the CNMC may complete the registration through an authorized representative. Refer to Registering Through Talkdesk earlier in this guide for more information.