There have more than 300 cases since April 2019 of attackers trying to gain control of UK mobile phone numbers by obtaining porting authorisation codes (PACs)
Source:
https://www.newscientist.com/article/2228252-phone-number-theft-through-sim-jacking-is-on-the-rise-in-the-uk/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home