Mobile phone billing lets you pay for your iTunes Store, App Store, and iBooks Store purchases and your Apple Music membership on your cell phone bill.
Here's how to use it:
On your iPhone, iPad, or iPod touch
● Open the iTunes Store or App Store app.
● Scroll down the bottom of the screen and tap your Apple ID.
● Tap View Apple ID. You might need to sign in.
● Tap Payment Information.
● Under the list of payment options, select Mobile Phone.
● If the phone you're using is the one connected to the carrier plan that you want to bill to, select "Use This Mobile Number.” Then tap next.
● If you don't see "Use This Mobile Number" or you want to use a different number, tap "Use a Different Mobile Number," then continue with the steps in the next section. If you're not using iOS 8.4 or later, you'll need to enter your mobile phone number manually.
● Apple will use the mobile number of the iPhone you're on to check with your carrier and confirm that you can be signed up for mobile phone billing. You might see a screen that says “Verifying” while this happens.
Other countries that support mobile phone billing include: Belgium, Germany, Japan, Norway, Russia, Saudi Arabia, Switzerland, Taiwan, and the United Arab Emirates.