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UK mobile networks are introducing additional restrictions in respect of SMS alphatags (sender IDs) in order to reduce the risk of spam/spoofed messages.

As of 1st June 2023 the following amended rules shall apply-

  • Alphatag (sender ID) allowable characters to include only:
  • A to Z (Uppercase), a to z (Lowercase), 0-9, special characters  ‘ ‘ (space), ‘.’ (full stop), ‘&’ (ampersand), ‘_’ (underscore), ‘-‘ (Dash/hyphen)
  • Maximum of 11 allowable characters
  • Alphatag needs to be to pre-registered with PageOne

What do I need to do?

The majority of customers will not need to do anything, but we have identified a small number of alphatags that include characters outside of the new rules – will notify these customers individually. As of 1st June 2023 you should ensure that any alphatags used either via PageOne Connect/Flare services and/or API connections adhere to the above rules, otherwise messages may be rejected by certain mobile networks.

If you have any questions regarding existing or new alphatags, please contact PageOne Customer Support team at