There is a strict system in place for violating the rules: https://www.nacha.org/NSfines https://www.nacha.org/NSfines But if things occur on accident, there

There is a strict system in place for violating the rules: https://www.nacha.org/NSfines https://www.nacha.org/NSfines But if things occur on accident, there is a "Returns" process for handling it. It looks like the author intends to cover that, at least partially, in the next installment. Here is a list of return codes if you want a hint: http://www.mainstreetmerchantsolutions.com/ach-return-codes http://www.mainstreetmerchantsolutions.com/ach-return-codes