Pay-by-phone lets you buy online and charge purchases directly to your monthly...

https://research-wiki.win/index.php/What_Is_the_Confirmation_Step_in_Carrier_Billing_Checkout%3F

Pay-by-phone lets you buy online and charge purchases directly to your monthly phone bill or prepaid credit. It’s a simple, secure way to pay without needing a credit card or separate account. Perfect for quick checkouts on mobile devices.