06-11-2019 10:38 - edited 06-11-2019 10:41
Do you mean unlock? If so, follow the guide here Guide: Unlocking an O2 phone to use a different SIM card
Most O2 phones are sold unlocked now, so try another network sim first.
on 06-11-2019 10:39
There is a guide for this:
Please note, this is not customer services and we cannot access your account. Do not publish personal details (email, phone number, bank account).
Link to our guide on how to contact them can be found here
on 06-11-2019 11:14
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)