My guess is it’s cause checking account string length is variable, the system that stores the info gets it all. But when read by the process generating the ACH

My guess is it’s cause checking account string length is variable, the system that stores the info gets it all. But when read by the process generating the ACH batch file it’s dropping the last character. I can’t be specific but I feel like I’ve seen this occur with raising an exception in some language/environment. It’s essentially reading a full varchar(17) into a varchar(16) so the last character gets chop’d. I think, while possible, 17 character account numbers is quite rare. If it were more common it would be a massive problem and surely Amazon Pay would be well aware/compelled to fix.