on 02-10-2018 05:23
@Sean-84 What is it exactly that you're trying to do? Are you porting your number in from another network? Have you looked at this page? https://www.o2.co.uk/help/phones-sims-and-devices/how-to-keep-your-mobile-number
Here are the contact numbers for customer service: https://www.o2.co.uk/contactus
on 02-10-2018 06:28
If the new SIM is due to losing your old one, call customer services to have the temporary block lifted off your account.
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)