The Check Clearing for the 21st Century Act (or Check 21 Act) is a United States federal law, Pub.L. 108–100, that was enacted on October 28, 2003 by the 108th U.S. Congress. The Check 21 Act took effect one year later on October 28, 2004. The law allows the recipient of the original paper check to create a digital version of the original check, a process known as check truncation, into an electronic format called a "substitute check", thereby eliminating the need for further handling of the physical document. In essence, the recipient bank no longer returns the paper check, but effectively e-mails...

Remote deposit refers to the ability to deposit a check into a bank account from a remote location, such as an office or home, without having to physically deliver the check to the bank. This is typically accomplished by scanning a digital image of a check into a computer, then transmitting that image to the bank, a practice that became legal in the United States in 2004 when the Check Clearing for the 21st Century Act (or Check 21 Act) took effect. This service is typically used by businesses, though a remote deposit application for consumers has been developed and has begun to be implemented...