A type of
mobile phone service subscription which allows cellphone owners to pay in advance for talk time, and add add more airtime as needed, by day, week or month. Pay-as-you-go services require no contract, and often no sign-up fees other than mobile phone service hook-up. Usually airtime is purchased in the form of a calling card where the user inputs a code from the calling card to use the purchased airtime minutes. Also called a
pre-paid service.