Cannot access O2 app to pay my bills

[KE4]

I haven’t been able to log in to the O2 app in months 

[MI5]

@KE4 

Try online https://mymobile.o2.co.uk/
If using the app, try deleting, rebooting phone and then reinstall the app.
This is a customer to customer community, not O2.
You need to contact O2.
Message them on Social Media. Facebook (https://o2uk.co/O2CFB) , Twitter (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG) or give them a call on 202 or 0344 809 0202 (contract) 4445 or 0344 8090222 (PAYG)
Unlikely that you'd get help in store, but may be worth a last resort try.

[Oxonian]

If you haven't been able to log into MyO2 "in months", how have you paid recent bills ? If you know how much your bill is, payment by bank transfer comes into play :-

Guide: How to Pay Your Bill (Airtime & Device Plans) 

You can also avoid future issues by setting up a direct debit. 👍

[MI5]

Probably already being paid by DD or the account would have been terminated by now.