Beginning iOS Game Center and Game Kit: For iPhone, iPad, and iPod touch

Test Accounts and Testing Purchases

If you were to try and purchase one of your items in the Sandbox now, you would receive an account error. You need to first create a new test account in order to be able to test purchases without being charged for them. To set up a new test user, you need to log in to iTunes Connect (http://iTunesConnect.apple.com). Select the Manage User section from the main screen of iTunes Connect; from here, select the option for a new Test User.

Test users do not need to use a real e-mail address, and you will want to select something quick to type and easy to remember, such as [e-mail]. Although you do need to enter a date of birth and other identifying information, there is no reason you cannot fabricate this data. ...