Submit ACH transactions across Same-Day ACH's three daily windows

Steps

1. Confirm your ODFI's cutoff times for all three Same-Day ACH submission windows: Window 1 closes in the morning (Eastern), Window 2 closes in the afternoon (Eastern), and Window 3 closes in the early evening (Eastern); exact times are published by NACHA and may vary by ODFI
2. Build and submit your NACHA-formatted ACH file to your ODFI before the target window's cutoff; files received after a cutoff are held for the next available window
3. Window 1 entries settle the same business day in the afternoon; Window 2 entries settle the same business day in the late afternoon/early evening; Window 3 entries settle the same business day by end of day — confirm exact settlement times with your ODFI
4. Ensure the SEC code and transaction amount comply with Same-Day ACH eligibility; entries exceeding the per-transaction dollar limit set by NACHA are ineligible (verify the current limit with NACHA as it has been raised over time)
5. Monitor for R-returns (e.g. R01, R02, R03) that can arrive as soon as the settlement window closes; process returns promptly to avoid balance errors