How do I cancel one number from a multi-phone contract

[C01]

How do I cancel one phone on a multi phone contract 

[pgn · Accepted solution]

Unless it is the lead phone, and all others have MyO2 access, it is going to need a call to O2, @C01 - numbers here: Guide: Coronavirus Community Help and Support 

Guide for cancelling a single phone, simply on its own MyO2, here: Guide: Cancelling Your Contract