A read head system has a housing and a read positioned in the housing with a slot for swiping a magnetic stripe of a financial transaction card with the slot utilized to enable a financial transaction between a buyer and seller. The read head reads data on the magnetic stripe and produces a signal indicative of data stored on the magnetic stripe. The read head includes an output jack configured to be coupled to at least one of a audio jack or microphone port of a mobile device. The read head provides the signal to the mobile device. The slot is oriented and sized to reduce torque applied on the read head as the financial transaction card is swiped through slot in order to maintain accuracy and reliability of the data read by the read head. Decoding of the signal is performed in the mobile device. The decoding includes determining pulses in the signal and converting at least some of the pulses to characters.