A postage metering lock-out security system is disclosed for use with electronic postage meters and for use with a postage metering system that operates in conjunction with a users computer and printer that prints postal value. With the lock out security system, in order for postage to be printed, the postage-metering control unit must receive a valid signal or password. The password may also be used to identify a particular user for accounting purposes. The metering system can also be provided with an internal clock so that metering may take place only within circumscribed times. An additional security feature is provided by an automatic call-back for postage recharging in order to assure that the meter is physically located at the appropriate location.