Check 21 is a new law that allows financial institutions to substitute a machine-readable image of a check (a "substitute check") for an original check. This image is used for collection or return rather than the original paper check. This law went into effect on October 28th, 2004.

Check 21 was created to speed up collection times, reduce collection costs, and increase security of member financial information. By removing the transportation of paper checks via ground or air, your information is more secure, and your checks will clear faster.