Carrier billing lets you pay for apps, games, or digital content by adding the...

https://troyaeco194.theglensecret.com/is-carrier-billing-good-for-subscriptions-or-better-for-one-time-buys

Carrier billing lets you pay for apps, games, or digital content by adding the cost to your phone bill. If you have a monthly plan, the charges appear on your regular statement. For pay-as-you-go users, the amount is taken from your prepaid balance