If the codes fail or you do not know your barring password, O2 can remove the restriction remotely from their side.
If you are an O2 customer in the UK , the most common reason for being unable to make calls is actually "Spend Cap" limits rather than traditional Call Barring. I have included instructions for both scenarios below. remove call barring o2
To remove call barring on O2, you can typically disable it through your phone's menu or by using the default O2 barring PIN, which is 0000 . If you encounter a network error or have an unpaid bill, you may need to contact O2 customer service directly by dialing 202 from your O2 mobile. How to Remove Call Barring on Android If the codes fail or you do not