A dual purpose test is when an auditor performs an audit procedure that uses the same transaction to approve both test of controls and substantive testing.
An example of a dual purpose test is when an auditor inspects checks to verify the validity of the amount, at the same time search the checks for the proper signature required for checks to clear. This test allows the auditor to perform test of controls in that the auditor will see if the correct signature is on the checks over a certain limit as well verify the validity and accurateness of the amount stated on the check.
