90 codes that cover most of what an originator sees. Each one carries the decision: retry or stop, which return rate it feeds, how long the receiving institution has to send it, whether a written statement is required, what the guidance rests on, and when it was last checked.
On a rail fact, every detail line names the section or instrument it rests on and whether that is a rule, a law, operator guidance, or observed practice.
Three return rates Nacha measures over a rolling 60-day window. Select one to see only the codes that count toward it.
Breaching 0.5% is a rules violation on its own. The 3% and 15% levels are inquiry thresholds: crossing them lets Nacha require your ODFI to investigate and reduce the rate, but it is not automatically a violation. Most codes below count toward one or more of the three rates; some (credit-only and enrollment returns) count toward none, and each code's card says which.