Abstract: An interface apparatus and method for transmitting data between a host computer and a telecommunication network without requiring special host-based computer programs to communicate with the interface apparatus. The invention uses existing ports of the host computer, utilized in their standard method of operation, such as driving a printer or communicating with a workstation. This reduces cost, simplifies use, and permits the use of the telecommunication interface apparatus with any computer utilizing its existing programs. The interface apparatus scans the beginning of a message for a command code comprising a string of special characters and the addressee number and/or code. If such a code is detected, the message is transmitted over the telecommunication network. Otherwise, the message is passed through the interface apparatus unchanged to be printed.