Patent ID: 7577609

Claim:
A method performed by a computer system on behalf of a guarantor of payment for purchases, the method comprising the computer system receiving from a user a request to send to said user at least one certificate, said request containing at least information that verifies the identity of said user, the computer system, responsive to said request, and upon authenticating said user, determining a maximum amount and a period of time during which said guarantor is willing to guarantee payment for purchases by said user, the computer system sending to said user a certificate guaranteeing payment up to said maximum amount for a purchase by said user from a supplier in a transaction carried out over a network, so that said user is enabled to enter into said transaction using said certificate as a form of payment that will be accepted by said supplier, said certificate including expiration information corresponding to said period of time, the computer system receiving said certificate and an electronic record of said transaction from said supplier, said electronic record including at least the type of said purchase and the price, the computer system, after receiving said certificate and said electronic record of said transaction from said supplier, making payment to said supplier for said purchase a) without having received from said supplier any request for assurance relative to said certificate or relative to said guarantor's guarantee to make said payment, and b) without providing any such assurance to said supplier, and the computer system, after receiving said certificate and said electronic record of said transaction from said supplier, billing said user for the amount of said purchase in a billing statement that indicates at least said type of said purchase and said price, the computer system including one or more processors.