Messages containing sexual/adult content are prohibited. Marketing messages should also have a clear opt-in and opt-out procedure.

The use of International Numbers for A2P messages is being blocked by the UK Mobile Network Operators. In addition, unauthorized variants of legitimate SenderIDs, i.e. SIDs belonging to banks and government agencies as well as generic, non-branded Sender IDs (eg. “Verify”, ”OTP”, ”Code”, etc.), are also being filtered. 

Therefore it is required to use a branded, Alphanumeric SID and/or UK Domestic numbers for your A2P messages.

Sender ID Registration

If you would like to continue sending SMS to the United Kingdom, you will need to submit an approval request form and whitelist all the Sender IDs that you use.

Instructions on how to submit the form can be found in this Help Center article. 

From June 12th, 2023, MessageBird will start BLOCKING all NEW unregistered SMS Sender IDs going to the United Kingdom. 

If you have any questions, please contact Customer Support.