Carrier billing lets you buy apps, games, or services and pay for them through...

https://www.stealth-bookmark.win/carrier-billing-lets-you-buy-apps-games-or-services-and-pay-through-your

Carrier billing lets you buy apps, games, or services and pay for them through your phone bill. Instead of using a credit card, the charge is added to your monthly bill or taken from your prepaid phone credit