Pay-by-phone lets you make purchases online and charge them directly to your...

https://web-wiki.win/index.php/What_Should_I_Tell_Customers_About_Carrier_Billing_and_Privacy%3F

Pay-by-phone lets you make purchases online and charge them directly to your mobile phone account. Whether you have a monthly phone bill or use prepaid credit, this option simplifies checkout by removing the need for credit cards or bank info