Carrier billing lets you buy digital goods or services and have the cost added...

https://kilo-wiki.win/index.php/Why_Does_Carrier_Billing_Show_Up_as_a_Weird_Line_Item%3F

Carrier billing lets you buy digital goods or services and have the cost added to your monthly phone bill or taken from your prepaid credit. It’s a simple payment option that doesn’t require a card or separate account