Methods of billing telephone calls in networks that utilize shared modem pools. A request from a user of the network is received along with user identifying data. The user identifying data is correlated with records in a database of user identifying data and if a match is found, the call is passed through the network. The user has then been authenticated as a valid user of the network and can be billed accordingly, even though a random modem in the modem pool was used to place the call. This allows the user to be billed for the call so that the owner of the modem pool is not left financially responsible for the long-distance and/or other toll charges incurred by the user in making the call. The methods also ensure that the modem pool owners can bill for all calls, thereby enhancing the network's revenue stream.