Abstract: An automatic, portable digit outpulser for use with a telephone is disclosed. In one preferred embodiment, the outpulser resembles a credit card encasing electronic circuitry and having a low-profile acoustic device mounted on one surface of the card for acoustically coupling the outpulser to the transmitter of a telephone. Optical and mechanical coupling arrangements are also disclosed. The electronic circuitry includes a memory for storing representations of telephone digits to be outpulsed and multifrequency signal generating circuitry for generating audio frequency signals, similar to those generated by a standard telephone equipped with a multifrequency key set, in accordance with the stored digit representations. The memory also contains control data words which are individually alternated in sequence with digit words. The signal generating circuitry is directly responsive to the digit and control words for generating both digit signals and interdigital timing periods.