The Check Clearing for the 21st Century Act, more commonly known as 'Check 21', came into effect on Oct 28th, 2004. Essentially a means of ending the slow, costly and inefficient reliance on the physical transportation of paper checks; Check 21 allows banks to transmit electronic images of the check through the clearing process. While the advantage of this legislation to banks is self-evident, what is less clear to many merchants and retailers is how they can benefit and how Check 21 will affect.