From September 15, 2026, Spain requires every alphanumeric Sender ID used for SMS to Spanish mobile numbers to be listed in the CNMC Alias Registry.
This article explains what's changing, who is affected, and how to submit your Sender ID for compliance through Omnisend.
Before You Begin
This applies if you send SMS messages to Spanish mobile numbers using an alphanumeric (branded) Sender ID.
Required for: Promotional campaigns, transactional messages, and automated notifications sent via Omnisend.
Authorized representative: Ensure this person has a Spanish digital certificate or eIDAS-ready before you submit. They'll need it to confirm the registration in the Spanish regulator's portal. Without this confirmation, your Sender ID remains unregistered.
After you register your Sender ID, use that value as your SMS Sender Name in Omnisend. Learn more about SMS Sender Name.
⚠️ Important: Spain has required Sender ID registration since September 15, 2026. Spanish mobile operators block messages sent with unregistered alphanumeric Sender IDs. Omnisend pauses these messages so they are not charged to your SMS credits.
What's Changed
Spain now requires all alphanumeric Sender IDs to be registered before they can send messages to Spanish mobile numbers. This protects consumers from SMS fraud and brand impersonation. Sender IDs must match your registered company name, trademark, domain, or another lawful identifier.
💡 What's an alphanumeric Sender ID? It's the branded name (letters and numbers, up to 11 characters) that appears as the sender name in your SMS. For example, "Omnisend" or "YourStore".
Key changes:
Verified Sender ID: Brands with a verified Sender ID continue sending to Spain as usual.
No verified Sender ID: Omnisend pauses SMS to Spanish mobile numbers before dispatch.
Other destinations: Sending outside Spain is unchanged. SMS subscription and Signup Form opt-ins continue working.
Note: Paused messages are not charged and do not affect your SMS credits.
Who Is Affected
You are affected if you send A2P (Application-to-Person) SMS messages to Spanish mobile numbers using an alphanumeric Sender ID. This includes:
Promotional campaigns (e.g., sales, offers)
Transactional messages (e.g., order confirmations, shipping updates)
Automated notifications (e.g., abandoned cart reminders, workflow messages)
Note: If you only send SMS with a numeric Sender ID (phone number) or a short code, registration is not required.
Required Information for Spain Sender ID Registration
Omnisend uses Path 2 of Twilio’s Spain Sender ID registration process. Before you submit the form, prepare the following information and documents:
Sender ID: The exact name that will appear in your SMS messages.
Company details:
Business name as registered with the relevant authorities
Company VAT number, fiscal ID number (NIF), or business registration number
Registered company address
Company website URL
Company phone number, including the country code
Legal representative details:
First and last name
Email address and phone number
Company and role
Legal representative ID number, such as a Spanish NIF, US TIN, passport number, or equivalent
Company Registration Certificate: Upload a PDF proving the legal existence of your company. Spanish or EU registration documents are preferred. US businesses should provide a CP 575 or 147C letter.
Proof of the right to use the Sender ID: Provide a company certificate, trademark or trade name certificate, domain ownership document, or other official proof.
Tax certificate: Upload a government-issued VAT, NIF, NIE, or equivalent certificate in PDF format.
Legal representative’s government-issued photo ID: Upload a PDF or PNG copy. Include the back side for a driver’s license or ID card.
CNMC Letter of Authorization: Download, complete, and sign the letter as the legal representative. Upload it in PDF format.
Messaging details: Indicate whether you send promotional or transactional messages, provide your estimated monthly SMS volume to Spain, describe your messages and recipients, and include a sample SMS.
For the latest document requirements, see Twilio’s Spain Sender ID registration guide.
💡 International senders: Your registration is submitted through Twilio, Omnisend's certified telecommunications provider, to ensure compliance with Spanish requirements.
How to Submit Your Sender ID Registration
Omnisend handles the registration process with the Spanish regulator on your behalf. To start:
Step 1. Go to Store Settings → SMS.
Step 2. In the Sender's name field, enter or review your SMS sender name (up to 11 characters) → Click Save.
Step 3. Scroll to Countries that require sender's name registration → Find the row for Spain with "Action required" status → Click Resolve.
Step 4. Fill out the form and provide the required information (listed above) → Click Submit.
Once submitted, the status will change to "Submitted". Omnisend forwards your registration to Twilio, which submits it to the Spanish regulator.
Next step: The regulator will email your authorized representative with instructions to confirm the registration in the regulator's portal. A Spanish digital certificate or eIDAS is required to log in.
You'll receive an email notification once your Sender ID is verified or if any issues arise. Sending to Spain resumes after your Sender ID is verified. Until then, messages to Spanish mobile numbers remain paused.
⚠️ Action required by your authorized representative: The Spanish regulator requires your authorized representative to confirm the registration directly in the regulator's portal. Until they do, your Sender ID is not verified, and Omnisend keeps messages to Spanish mobile numbers paused. Make sure their digital certificate or eIDAS is ready before you submit, and that they are watching for the regulator's email.
Track Your Registration Status
After submitting your form, you can track your registration status under Store Settings → SMS:
Action required: You haven't submitted your registration yet.
Submitted: Your registration has been submitted and is awaiting confirmation by your authorized representative in the regulator's portal.
Verified: Your Sender ID is verified and compliant. You'll receive an email confirmation.
Rejected: Your registration was not approved. You'll receive an email notification. To resubmit, return to Store Settings → SMS and complete the form again with updated information.
Note: Only the Verified status restores SMS sending to Spanish mobile numbers. Action required, Submitted, and Rejected statuses keep Spain sending paused.
FAQ
What if I'm not based in Spain?
You still need to comply if you send to Spanish mobile numbers. Omnisend submits international registrations through Twilio as a certified provider.
What if my authorized representative doesn't have a Spanish digital certificate or eIDAS?
The Spanish regulator requires a Spanish digital certificate or eIDAS to confirm registrations in their portal. If your authorized representative doesn't have one, they'll need to obtain it before you submit. Contact a Spanish digital certificate provider or eIDAS issuer for assistance.
How long does registration take?
Verification typically takes up to 2 weeks after your authorized representative confirms in the regulator's portal. We recommend submitting at least 3–4 weeks before you plan to send.
What happens if I don't register?
SMS sending to Spanish mobile numbers is paused until your Sender ID is verified. Omnisend stops these messages before they leave the platform, so you do not spend SMS credits on traffic that Spanish operators would block. Sending to other countries is unchanged.
Will I be notified when my verification status changes?
Yes. You'll receive an email when your Sender ID is verified or rejected. You can also check the status anytime under Store Settings → SMS.
What happens if my registration is rejected?
Reach out to our Support Team to confirm the rejection reasons. Then, you'll need to resubmit the form again in Store Settings → SMS. Make sure all documents are complete and your Sender ID is clearly linked to your registered business name, trademark, or domain.
Can I use multiple Sender IDs?
Yes. But each Sender ID must be registered separately. Repeat the submission process for each one.
Does pausing SMS sending to Spain unsubscribe contacts?
No. Spanish visitors can continue subscribing through Signup Forms, and their SMS subscription status remains unchanged, while sending to Spain is paused. Sending resumes after the Sender ID is verified.
Need help? Contact our support team via live chat or email at [email protected].