HopeLine Key Serial Number
usage is usually measured in minutes, and the charges are fixed by the operator. there is also a prepaid option, but this means that users are billed for the number of minutes used in a particular billing period. unlike a post-paid contract, the subscriber is not necessarily billed for the time he or she has the phone.  in addition, subscribers to mobile phones may be able to make voice calls and receive text messages, even if they do not have a long-term contract with the mobile operator.
HopeLine key serial number
mobile phone service is generally charged by the minute, with the charges often based on the length of the call or the number of the recipient(s).  a short call can be charged at rates as low as one cent per minute, while a long-distance call can cost several dollars. some mobile phone plans are "pay-as-you-go" and allow the subscriber to purchase minutes on a per-call basis.  this is in contrast to pre-paid or pay-as-you-go plans, where the subscriber must commit to a minimum usage.
since most mobile phone subscribers are unable to afford a long-term contract, there are opportunities for fraud.  users may receive calls from numbers other than the one listed as the subscriber's number. 
to avoid becoming a victim of mobile phone fraud, users should register their phone number.  in the united states, there are several organizations to assist consumers with this process.  in many countries, it is sufficient to register the number. 
the hopeline pre-paid application allows for the purchase of airtime, the use of which can be either for a limited period of time or unlimitedly. the airtime can be used for any purpose and, after the use of the airtime, can be billed to the user's account with the hopeline provider.  the user is then able to activate the phone and place or receive calls without incurring any additional fees. in the event of the phone being lost, the airtime can be used for the duration of the call and will be billed to the user's account with the hopeline provider.