United Kingdom (UK) +44

Updated 4 weeks ago

Upcoming Sender Restrictions

In an attempt to fight the ever-increasing smishing & phishing in UK, BT/EE has put together a series of measures & restrictions in their new Code of Conduct, which Sinch, as a Tier 1 partner, has agreed and committed to.

The first measure that will be put in place impacts international numeric, short code senders, some generic sender IDs & special characters, please see below.

From the 3rd of July 2023:

• International numeric sender IDs will be blocked by BT; exceptions can be made on request, please talk to your account manager to request an exception.

• Short codes that don’t follow UK short code format (five digits starting with 6-8) will be blocked by BT; approval can be given upon request for 3 & 4 digit short codes and short codes not starting with 6-8 (eg, Irish companies using short codes starting with a 5), please talk to your account manager to request approval.

• Sender IDs going forward will be expected to be brand centric - to start with, BT will be blocking generic senders “Alert”, “Verify” & “Info” AND senders containing any of these three generic terms; exceptions can be requested for the likes of “SinchFraud” (as the brand is part of the name), please talk to your account manager to request an exception.

• Sender IDs containing special characters will also be blocked by BT. Please, see below the only characters that BT will support in the sender ID from July on; any other character not listed below will be considered a ‘special character’ and therefore subject to blocking on the operator side, please talk to your account manager to request an exception.

** Supported Sender ID Characters **

A to Z (Uppercase) . (Period/Full Stop) A to Z (Lower case) (Dash) - 0 to 9 (Numeric) _ (Underscore) (Space) ‘ ‘ Ampersand &

**Currently on our Cloud/Online product, only verified clients can send messages to the United Kingdom; please contact your account manager if you wish to use this product to send to UK.

***Flash messaging not supported in the UK.

This is a fully featured route and delivery to ported numbers is supported.

When Sending an SMS through our platform, we give you a few options:

  • A shared number (default) - we assign a number to the outgoing SMS so the user can reply. You can setup rules for incoming SMS, anything is possible.
  • Your mobile number - replies will be sent to you as an SMS. Replies will be sent to your mobile number and will not show on the account dashboard.
  • Your business name - e.g. "MyCompany". The receiver can't reply. This can be 11 characters maximum with no spaces.
  • Your dedicated number - you can purchase a ClickSend dedicated number. You can setup rules for incoming SMS, anything is possible.

Messages will be blocked by the network if the number is a Lyca mobile originating number.

The range 74402 is blocked as Lyca mobile prefixes(senders) are not allowed due to grey route blocking protection on our platform. The recommended action would be to not use any senders that start with 74402 against 3-UK numbers.

The ranges 44844 and 44845 are blocked for Fax numbers to limit suspicious spam calls.

Regulations and Best Practices


  • Required. The content provider should be able to demonstrate proof of opt-in in the event of an operator audit or a user complaint.


  • Required. The content provider is responsible for opting out the users from their databases.

SMS Marketing Messages must state that they are free by including in the message ‘free message’ or ‘freemsg’. The ability to opt out of future marketing messages must also be stated in the body of the message e.g. ‘to unsubscribe reply STOP to XXXXX’.

It is recommended that all STOP Command MOs are Free to user.

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