You have a lock screen password on your Windows Phone, right? It’s the smart thing to do in case you misplace your phone. Another layer of security is the Wallet Pin. This one is a little different. It’s not required, but it’s a good way to prevent accidental or unauthorized purchases by children or anyone else who has access to your phone. We’ll show you how to set it up in our how-to video.
More details: http://www.windowscentral.com/how-to-set-wallet-pin-purchases-windows-phone-store