Methods are provided for metering the usage, on a group of lines subject to a group user agreement, of the data processing capacity of a network. Implementations include steps of receiving usage reports from respective lines of the group at least when usage quotas granted to the lines are exhausted; maintaining a total, over the group, of usage that has been reported by the lines and of outstanding usage quotas that have been granted to the lines; and maintaining a comparison between the total outstanding group quota and a limit that depends on the total reported group usage, so as to detect violation events when said quota violates the limit. Upon occurrence of violation events, instructions for the processors serving respective lines to reallocate quota are sent selectively.