A credit-card radiotelephone for a vehicle with a door includes a radio transceiver and a control unit with a telephone handset, credit card reader, hookswitch and door switch. The telephone handset has a microphone, a speaker, and a dial. The radio transceiver has a transmitter, a receiver, and a first microprocessor for electronically locking and unlocking the radio transceiver. The credit card reader reads a credit card number and produces an output indicating the read credit card number. The control unit also includes a second microprocessor coupled to the credit card reader for receiving the read credit card number and determining if the read credit card number is valid, coupled to the first microprocessor, hookswitch and the dial for electronically unlocking said transceiver and placing telephone calls when the read credit card number is determined to be valid, and coupled to the door switch for electronically locking said transceiver means when the door is opened.