I have written exports from various payroll systems to produce NACHA compliant ACH files to upload to banks, every time there was a problem the bank would get back to us through the customer and we would get super weird or vague responses.
In the future I am going to ask for the return codes ( https://zenpayroll.com/ach_return_codes) listed in the article, very useful bit of info, thanks!
Writing NACHA exports for an online banking loan repayment system was the worst. Being a Junior Dev at the time, and having my only guidance being a NACHA handbook, with no banking experts to actually explain things, knowing millions of dollars per year would go through the app... Man. Terrifying.
