Originally Posted by Ron Bennett

One can simply use a valid ABA number along with a madeup account number to get through. There's no real-time verification for e-checks.

3rd party processors do some validation using various heuristics / blocklists, but that still leaves a lot that can get through.

Bottom line is use a 3rd party processor for echecks, and figure many bogus echecks will still slip through. And if possible, add some frontline fraud detection (IP block lists, site usage patterns, etc) prior to passing echeck transactions to the 3rd party processor.

Ron