Carrier billing lets you buy apps, games, or digital content and charge the...

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

Carrier billing lets you buy apps, games, or digital content and charge the cost directly to your phone bill. If you have a monthly plan, the purchase appears on your next bill. For pay-as-you-go users, the amount is deducted from your available credit