What is Check 21?
Check 21 is the Check Clearing for the 21st Century Act, or Check 21 Act. This federal legislation authorizes financial institutions to truncate checks and exchange images instead of paper checks. Check 21 allows banks to create a special paper copy, called a substitute check, of an original check.
A substitute check is a legal document, with all the rights and obligations of the original check. It is a reproduction of the original check. It includes all information and endorsements from both the front and back of the original check. You can use a substitute check as proof of payment.
More information on this topic can be found at Check Clearing for the 21st Century - FDIC.