Prepaid and Postpaid
VoIP origination is mostly prepaid nowadays. This means that the customer pre pays the amount either through his credit card or buys a prepaid calling card. As soon as the card or credit is finished, the customer is disconnected and needs to recharge the account or buy a new card from the market. In postpaid the ITSP sends an invoice at the end of the accounting period usually a month and the customer pays later.
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