There are plenty of free apps available for Google Android devices - whether they're smartphones or tablet PCs - that don't need you to register any form of payment method. However, if you do plan to download an app that is paid-for, then you will need to register your credit or debit card with Google using its Google Wallet payment service.
While we've already shown you how to add credit cards to your Google Wallet account in our How to purchase an app from the Android Market article, it's worth bearing in mind if you want to delete any cards then you have to manage your Google Wallet account from a PC using Google's dedicated website.
Here's how to manage your Google Wallet account.
Open a web browser and navigate to the Google Wallet homepage. Now press the Sign-in button in the top right-hand corner.
You'll be asked to enter the email address and password assigned to your Google account. You'll be presented with a list of all your transactions using the service.
To edit or delete card details, click on Payment Methods on the left hand-side of the window and then either press Edit or Delete, which are marked in blue underneath an image of a credit card. Edit allows you to change the expiry date, security code and address the card is registered to, but not the card number.
If you press Delete, you will, be asked to confirm you want to remove the credit card details from your account. Press Yes, delete it to continue with the card's removal. You can also add a new payment method here, by pressing New Card which is marked in a red box at the top of the window.
If you pay for physical goods and services using Google Wallet, the delivery address will be taken from the address book in Google Wallet. To change an existing address or add a new one, simply press Address Book from the left hand side of the Google Wallet window and then either press the red box marked New Address to add a new location or press Edit or Delete under the existing address to amend or remove it completely.