Use your PAYG credit to buy stuff on Google Play

If you've got any SIM cards knocking about with some credit left on them why not use it up to buy stuff from Google Play.

If you buy your handsets on PAYG to get them cheaper you'll have to top up. Here's how to make sure that credit doesn't go to waste:

1 Remove your usual SIM from your phone and insert the SIM with the unwanted credit.
2. Start up your phone and turn on data (even if WiFi is on).
3. Open Google Play, go to My Account, Payment Methods, Add Payment Method, Mobile Billing.
4. Choose whatever paid-for app you want and make sure you select Mobile Billing as the payment method.
5. You can now stick your usual SIM back in your phone but you will still be able to charge apps to your SIM with the unwanted credit. The payment method also shows up in other devices such as tablets.
6. Once your credit has been used up, go to Google Wallet and remove that SIM.

Often you can get deals on PAYG that come up cheaper than SIM free handsets. Before the ability to pay via your mobile bill it would have been a case of using the credit or bunging it in a draw somewhere.