Fecha de publicación: 19/09/2002 Fuente: WIPO "royal booby" A known micro-payment system suffers from a problem of needing increasing network bandwidth as the granularity of the micro-payment decreases, thus increasing the latency of the processing of each micro-payment. The present system seeks to address this problem. There is disclosed a method, performed in an interactive client server system, of charging micro-payments to a third party billing server on behalf of a user using the interactive client server system, said method comprising the steps of: requesting a billing authorization from a user of the interactive client server system; receiving an authorization including an address of a billing server (e.g. from a smart card); sending an authorization message to the billing server. The billing server determines from the authorization whether the user has a valid account at the billing server. A micro-payment value may be determined from the authorization. The interactive client server receives confirmation that authorization is acceptable to the billing server together with the micro-payment value. It then generates, on condition of a confirmed authorization, charge events having an associated charge in monetary terms. It then sums the charge for the charge events until the micro-payment value has been reached and sends the charge summation to the billing server to be debited from the user's account as a micro-payment. In this way finer granularity of micro-payment is achieved without increasing bandwidth use.