A pay-as-you-go phone refill is a service whereby a subscriber purchases credit or airtime to be able to make calls, text or use data on his prepaid mobile phone. Once the prepaid amount is exhausted, the subscriber may add credit by purchasing a refill or top-up card.
Refill cards come in various denominations, such as $10, $50, $75 or $100. Other payment options a subscriber may use include drawing funds directly from his bank account using an ATM, making a purchase using a swipe card, or making a purchase using a credit or debit card.
The advantages of a prepaid plan are that it generally costs less and spending and usage is controllable. Some mobile phone operators offer rewards to prepaid customers, such as free SMS, if a customer credits his phone with a certain amount.
Pay-as-you-go phones require no contract, unlike postpaid phones. Therefore, a prepaid user may switch his mobile phone operator whenever he wants. The user only needs to switch his SIM card.
However, with prepaid plans, credit bought may have a time limit. Most prepaid services have a 90-day time limit. In such cases, if a customer does not add more credit before the expiration date, he loses the remaining balance.