Mobile digital currency

Abstract

A method includes providing a first payment account that is issued by a first financial institution and enables an accountholder thereof to make payments at merchants via a closed-loop payments network corresponding to the first financial institution and mobile person-to-person payments using the payment account. The method includes enabling a second payment account that is issued by a second financial institution to be electronically linked to the first payment account and used as a source of funds. The method includes providing a mobile operating system and enabling a plurality of merchant-specific payment accounts to be associated with a mobile communications device having the operating system. The method includes determining whether a merchant-specific payment account that is accepted only by a particular merchant is available to the accountholder via the mobile communications device and receiving a fee when the first payment account is used for a purchase.

What is claimed is: 
     
         1 . A system comprising:
 a prepaid payment account of a user of a mobile communications device, wherein said prepaid payment account has a balance of funds available for use in making a payment with the prepaid payment account; and   an amount of credit that is made available to the accountholder of the prepaid payment account,   wherein a decision to authorize or decline a purchase transaction attempted with the prepaid payment account comprises a comparison of a monetary amount of the purchase transaction with a sum of said balance of funds available in the prepaid payment account and said amount of credit,   wherein, when said monetary amount of the purchase transaction is less than or equal to said sum of said balance of funds available in the prepaid payment account and said amount of credit, then the purchase transaction is authorized and a corresponding approval message is transmitted,   wherein, when said monetary amount of the purchase transaction exceeds the sum of said balance of funds available in the prepaid payment account and said amount of credit, then said purchase transaction is declined and a corresponding declined message is transmitted.