A method of selecting one of a plurality of rate plans for cellular radiotelephone users each having corresponding user records from one or more cellular systems gathered in a billing pool, said billing pool including user records for at least a current billing period and a previous billing period, each user record including a current rate plan and usage information for the current and previous billing periods, said method comprising the steps of:
- a) selecting all user records from the billing pool for each cellular radiotelephone user which has non-zero usage information for the current billing period;
- b) creating a current usage pool and a previous usage pool by accumulating the usage information in the selected user records for the current billing period and the previous billing period, respectively;
- c) creating a summary user record for each cellular radiotelephone user by accumulating the usage information in all corresponding user records;
- d) appending current and previous usage pools to each summary user record;
- e) calculating costs for each cellular radiotelephone user based upon the accumulated usage information in the corresponding summary user record and at least two of the rate plans;
- and
- f) selecting for each cellular radiotelephone user the rate plan which has the lowest calculated cost.