One embodiment of the present method is for allowing a mobile subscriber to negotiate via a mobile terminal a trade of minutes by category according to a predetermined exchange rate as set forth by a service provider. In this embodiment the method may have the steps of: providing a plurality of categories of usage associated with a mobile terminal, the mobile terminal having associated therewith predetermined amounts of time respectively for the categories during a predetermined time interval; tracking, by the telecommunication network, respective time used by the mobile terminal in each category of the plurality of categories during the predetermined time interval; initiating, by the mobile terminal, a trade transaction with the telecommunication network; sending, from the telecommunication network to the mobile terminal, current amount of used time respectively in each category of the plurality of categories; selecting, at the mobile terminal, at least a portion of at least one remaining time in one category of the plurality of categories for transfer to at least one other category of the plurality of categories, for a respective category, a remaining time of the respective category being a respective amount of time during the time interval less a respective current amount of used time for the respective category; sending, from the mobile terminal to the telecommunication network, the selection; and transferring, at the telecommunication network and according to the selection, at least a portion of at least one remaining time in one category of the plurality of categories to at least one other category of the plurality of categories. The system implements the method.