Won’t let me top up or add bolt on

[Adam38]

I’ve ran out of data so trying to buy a bolt on it won’t let me, I then try to top up to buy one that way and it won’t let me top up either 

[pgn]

All the ways to top-up are here, @Adam38 - assuming you are on a Big Bundle and not a Pay As You Go: Introducing "Rolling Plans"  - Guide How to Top Up (PAYG) 

There is usually not a problem giving O2 money, however making sure it ends up associated with the correct phone can be tricky...

Make sure if using Web TopUp that your phone number is correct, no refunds if you top up somebody else's phone by mistake:

[MI5]

@Adam38 

If nothing else works for you, call 4445 for customer service or message O2 on their socials.

Guide: How to find help & contact O2 

[Oxonian]

I have never experienced a problem @Adam38 with buying a PAYG top-up voucher from a local shop and following the instructions thereon ; just make sure that you 'phone from the number that you want to top-up.