The prenote is a zero-dollar test in which a bank or company can make a transaction of zero dollars and zero cents to ensure bank credentials are verifiable. Once a prenote test has been passed, direct deposit will be set up.

This is a much better version of the seldom-used post-note test, where they just watched to see if direct deposit went through, and if it failed, they would send a zero-dollar test to see if it failed again.