Abstract: The present disclosure provides a cognitive multi-card handling system for automatic testing of transaction apparatus and a testing method. Conventional techniques such as manual testing and automatic testing require lot of testing time and have limitations to test with number of test cards and different card types, identifying required test card from heterogeneous stack of multiple test cards and without much manual intervention. The disclosed cognitive multi-cards handling system comprising a mechanical sub-system and a multi-card handling sub-system provides a mechanism to test number of test cards of different card types, identify and eject the required test card from a heterogeneous stack of multiple test cards, as per the test case to perform the transaction operations. The disclosed testing method ensures smooth completion of automatic testing process consisting of thousands of test cases without manual intervention.