on 23-02-2020 15:29
@Kate7395 You need to speak to customer service: https://community.o2.co.uk/t5/Welcome-News/How-to-find-help-amp-contact-O2-A-Guide/m-p/1201416
If you are unable to use any of those numbers you can call for free from any phone on 0800 032 1402
If the account is halted just because of inactivity it will depend on how long the account has been inactive. If it's been too long, the number may have been reassigned. You'll need to speak to customer service to find this out.
on 23-02-2020 16:55
Once reinstated, your credit may take 24 hours to be applied if you had any on your account.
In future, you need to make a chargeable call or send a text at least once every 6 months and top up at least every 999 days.
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)
23-02-2020 21:47 - edited 23-02-2020 21:47
Just to add in case the number you had was brought in from another service provider (and this is a long shot)
Ported numbers get returned to the original network operator where they are required to remain in quarantine for 6 months before they can be allocated to a new customer.
Have a look here http://static.ofcom.org.uk/static/numbering/index.htm#pers (Personal Numbering, Radiopaging & Mobile Service numbers) which will open in an Excel spreadsheet.
Look up your five digit prefix which will show whom it was originally allocated to (note that Virgin Mobile numbers like mine was for example actually come under EE)
You could try and write to them but if they agree be prepared to have to spend a tenner to activate a PAYG SIM on their network to have it attached to and then text PAC to 65075 tp request a PAC to port out.
Note that a number is never yours which is why I've said this is a long shot and the chances of it working are slim but if you don't try you'll never know.