Handle UK number restrictions

Got an email from Twilio:

> UK carriers have implemented restrictions on messaging traffic originating from international long codes to UK phone numbers; they consider the use of international long codes for Application-To-Person (A2P) SMS as an abuse of Person-To-Person (P2P) routes.
>
> Due to these restrictions, in 2023, Twilio began blocking all SMS messaging traffic sent from international long codes to UK phone numbers on the BT and Sky Mobile networks.
>
> Starting July 30, 2024, all SMS messages sent to the UK via international long codes, regardless of carrier, will be blocked. Going forward, SMS messages sent to the UK must be sent via an Alphanumeric Sender ID, a domestic UK long code, or a short code.

I'll need to come up with a way to solve this problem to take the project forward.