Pay-telephone station with deferred collection

A pay-telephone station equipped to handle local and long-distance calls includes a microcomputer which, at the end of a conversation or under certain conditions during a call, selectively collects predeposited payment items (coins, bills and/or prepayment entries of subscription cards) of different denominations calculated according to the debt incurred and to the denominations available to optimize the refunding of any excess to a user. The microcomputer also determines, upon the start of dialing by a caller, whether the initial deposit suffices for at least the basic charge on the type of connection (local or trunk call) sought to be set up and, if it does not, invites the user to make an additional deposit before aborting the call. The remaining credit balance is continuously signaled to the caller on a display unit and, even before actual collection, is diminished according to the applicable rate in response to each metering pulse arriving from the exchange.