second hand sony phone need network unlock code

[sw11]

Hello,

My son has a second hand sony xperia x compact phone. It appears to be locked to o2 network.

How can I get a network unlock code. I can get the imei no 

Thanks,

Simon. 

[MI5 · Accepted solution]

@sw11 

Follow this guide Guide: Unlocking an O2 phone to use a different SIM card 

[sw11]

hello,

many thanks for the prompt reply.

i have tried the guide and the online form but it does not seem to work. It gives me a 405 web error at the final stage.

I wonder if that is because the original owner of the phone needs to request the unlock code?

Do you have any other suggestions?

I appreciate your help, it would be good if could contact o2 directly, but they do not seem to have an email account i can find.

Thanks

[MI5]

@sw11 

If you need to contact O2.
All numbers are in this guide Guide: Coronavirus Community Help and Support 
When you call, you will be asked for the reason you are calling.
Stay silent for 15 seconds and you will be taken to the keypad options.
Press 2 for Everything Else
Press 5 for More Options
Press 7 for Anything Else which will put you though to someone.
You can also try saying "Upgrade" or "Fraud" to be connected to an advisor.
8.00am is the best time to call if you can.