20 Sep 2023

UK | Sender ID requirements

From July 3, 2023, new regulations governing the requirements for sender IDs used to send messages to the UK were enacted. Messages sent from sender IDs that don’t meet these requirements are likely to be blocked, so it’s important you take the necessary steps if you wish to send messages to the UK.

UK Sender ID requirements:

  • International numeric sender IDs will be blocked (non-UK numeric sender IDs).
    • This means that messages sent from international mobile numbers will be blocked. This includes:
      • Dedicated numbers
      • Shared number pool
      • Your own mobile number
    • At this point, it would seem that mobile numbers that are from the UK (e.g. 07700 900000) are still permitted to send SMS messages to UK numbers.

  • Short codes that don’t follow UK short code format (five digits starting with 6-8) will be blocked.

  • Sender IDs will be expected to be brand centric; Alpha Tags/Alphanumeric IDs containing generic senders (e.g., “Alert”, “Verify”, “Info” and similar variations) AND senders containing any of these generic terms will be blocked.
    • This means that all alpha tags must be recognisably associated with your brand. For example, a company called “ACME Co.” should ideally use “ACME” or maybe “ACME_Co” as their alpha tag, regardless of the purpose of the message. Suppose the message is for an ACME customer to verify their identity. In that case, sending from the alpha tag “VERIFY” will be blocked because the word “Verify” is not recognisably associated with ACME.
    • It’s likely that variants of these ID’s (e.g., “_Verify_”, “VER1FY”, “VER IFY”, etc.) will also be blocked in the future, so we advise against using them.

  • Alpha Tags may only contain the characters: a-z, A-Z, 0-9, and – or _.


Consequences of non-compliance:

UK carriers take “smishing” (phishing via SMS) very seriously. Customers sending SMS messages after July 3, 2023, from sender IDs that don’t conform to the above requirements may incur liquidated damage charges of up to £5,000.