SUPPORT.TWILIO.COM END OF LIFE NOTICE: This site,, is scheduled to go End of Life on February 27, 2024. All Twilio Support content has been migrated to, where you can continue to find helpful Support articles, API docs, and Twilio blog content, and escalate your issues to our Support team. We encourage you to update your bookmarks and begin using the new site today for all your Twilio Support needs.

Documents Required and Instructions to Register Your Alphanumeric Sender ID in United Kingdom

Before we begin

MEF’s SMS Sender ID Protection Registry was established to automate cross-stakeholder processes to reliably and quickly share information to facilitate an orchestrated blocking system. The online platform helps identify and block fraudulent SMS texts, protecting consumers, legitimate businesses and organizations falling victim to text messaging scams. It enables organisations to register the message headers used when sending text messages to their customers and limits the ability of fraudsters to impersonate a brand by checking whether the sender is the genuine registered party.

Due to requirements in United Kingdom, you must complete and return a Letter of Authorization (LOA) to Twilio in order to continue using MEF Sender IDs to send messages to United Kingdom. 

To avoid potential traffic interruption, you must complete the LOA and send it to by June 6, 2024.

The list of Protected Sender IDs can be found here.


To register your Alphanumeric Sender ID, please provide the following LOA document: 

  • Protected Sender ID Registration LOA Request - Client to Twilio (UK)

To get you up and running as quickly as possible, please fill out the document completely and accurately and provide any other required information. Use the examples provided for guidance. Note that mobile network carriers are very strict about the details! We highly recommend that you download the examples (hit right click, and select 'Save Image As...') and do a side by side comparison when you are filling out the documents.

Provide the necessary information

Once you have downloaded the forms, follow these general instructions: 

  1. Fill in the yellow highlighted fields—completely replace each field with your own information. If a field is not highlighted, don’t change it.
  2. If you have questions on how to fill in the required fields, refer to the annotated examples we provided for each field. 
  3. Have the documents signed by an authorized signatory of the Sender.
  4. In the highlighted fields, add the Sender’s letterhead and/or logo, stamp and sign where indicated.
  5. You can send the completed documents to 

Required fields include:

  • Company Letterhead
  • Organisation
  • Alphanumeric Sender ID
  • Website URL
  • Sample SMS templates
  • Name of authorized signatory
  • Signature of authorized signatory
  • Company Stamp
  • Title
  • Email Address

Screenshot 2024-03-12 at 9.53.08 PM.png


Have more questions? Submit a request
Powered by Zendesk