Pay-by-phone and carrier billing let you buy digital goods or services and...

https://milosimpressivejournals.quillnesty.com/posts/why-telecom-providers-are-involved-in-online-payments

Pay-by-phone and carrier billing let you buy digital goods or services and charge the cost directly to your monthly phone bill or prepaid credit. It’s a simple way to pay without needing a card or cash