O2

It's never been easier to top up your mobile using your credit or debit card. Just call the O2 Top-Up line free of charge by holding down 3 or dialling 4444 from your mobile phone. If you're calling from a landline, dial 08456 062 277 (calls charged at the local rate). Have your Debit/Credit card number ready and follow the simple step-by-step instructions. You'll hear a 'Top-Up successful' message when your call time has been credited and we'll also send you a text.

The credit / debit cards you can use to Top-Up are Visa Credit, Visa Debit, Electron, Mastercard, Maestro and Solo. You can Top-Up between £10 and £30 at a time.

The next time you use the same card to top-up you'll be able to use our Express Service - it's even quicker and easier as there's no need to register.

• You can top up £100 within a 30-day period, but within a 24-hour period the maximum amount you can top up is £30 (minimum top up is £10).
• If you're topping up with a Mastercard for the first time, you are limited to topping up to £20 within the first 30 days of use. After the first 30 days have passed, you can use your Mastercard to top up, up to £100 within every subsequent 30-day period, as usual.
• You can have three cards registered to your mobile phone at any one time or you can use one card to top up two different mobile phones.