The structure of the charges can vary depending on payment method (by direct debit, pre-payment meter, or credit transfer such as cheque), on whether it is an internet-only tariff, which part of the country the customer lives in, if the deal involves a fixed price, when the deal was launched, how long it lasts, and so on.

BBC: Ed Davey announces 'four core tariff' plan

Direct Operator Billing from MACH will enable Skype to bring a vital alternative payment method to these channels: Skype users will be able to charge their Skype credit to their mobile phone bill or pre-paid account, and enjoy the frictionless user experience gained from this payment method.

ENGADGET: Skype strikes deal with Mach to expand direct carrier billing for credit purchases