Substitute check
Substitute checks are digital copies of the fronts and backs of paper checks that provide the same legal protections and obligations as the originals, including serving as proof of payment.
Each check is formatted on a separate piece of paper a little larger than the original with the words "This is a legal copy of your check" appearing next to the image.
Using digital copies, which can be transmitted electronically, allows banks to process payments faster and more efficiently than they could when paper checks had to be routed through the check clearing system. Most banks destroy original checks once they've archived the substitutes, which means that you probably no longer receive cancelled checks with your bank statement.
Your bank may send you substitute checks but is more likely to provide either a line item statement or an image statement that has photocopies of the fronts and backs of cancelled checks grouped on a page. These are not substitute checks, although they can often be used as proof of payment.
If you need an actual copy of a substitute check, you can request it from your bank. However, there may be a fee.
Yahoo Finance - Cite This Source - This Definition- Check truncation, Debit, Electronic check conversion