Unlocking phone

[Dawnb]

I've swapped my O2 sim to a new phone and want to sell my old one.

How do I unlock it?

[Cleoriff · Accepted solution]

@Dawnb 

If your phone was bought after 2018, It wont be locked. O2 stopped locking their phones then

However Guide: Unlocking an O2 phone to use a different SIM card