The cellular telephone credit card calling system works in conjunction with a cellular telephone, a local cellular network and an IXC in a telecommunications network. The cellular telephone has a handset and a transceiver unit coupled together by a power and a communications bus. A credit card interface unit is coupled to the bus. The interface unit has a credit card reader and an electronic system which initially validates the credit card. The cellular telephone also includes electronic circuitry which establishes a first telephone communications link with the network and transmits, via the transceiver unit for the phone, to the network, credit card data, a cellular telephone ID data and the telephone number input into the handset by the user. Upon receipt of at least the credit card data, a network transceiver verifies the validity of the user's credit card. After the credit card has been validated by the IXC through a verification or validation computer service, the network transceiver then completes a further telephonic communications link between the cellular telephone, operated by the user, and the telephonic device associated with the input telephone number, that is, the third party's telephone. Since the network transceiver does not complete the call to the third party prior to validation of the user's credit card, the system operates in real time. Further, in a preferred embodiment, the network transceiver provides some type of indication to the credit interface unit that the credit card has been validated. Thereafter, the user is permitted to make additional cellular telephone calls without requiring further validation of the credit card data by the network transceiver.