O2 top up online
You can easily purchase O2 top up online via MobileTopup.co.uk and top up your O2 mobile within 30 seconds. You select the O2 top up amount, then you check the order and you pay the phone credit using one of the secure payment methods. After payment, you will receive the top up voucher code via email. You can then directly top up your O2 Pay as you Go Plan using the instructions below.
Using the O2 top up voucher, you can instantly top up your O2 Pay as you Go Plan. You call the O2 customer service by dialing 4444 from the mobile phone for which you would like to top up phone credit. You can also dial the number 08456 062 277 from a landline. Then you need to follow the recharge instructions which are provided during the phone call. Please make sure you have the voucher at hand during the phone call, because you have to enter the code during the call in order to top up your O2 phone credit.
You can check your O2 top up credit balance by dialing hotkey 2, or by entering *#10# and press the call button. Then your Pay & Go balance directly on the screen. It is also possible to dial 4444 with the phone for which you would like to top up the phone credit. Then you follow the instructions in the menu and your balance will be stated.
The O2 voucher has limited validity. An O2 top up voucher will expire after twelve months. So use your O2 mobile top up credit before the expiration date, otherwise the O2 top up credit will become useless.