Submit and process transactions across NACHA Same-Day ACH windows with correct effective entry date logic

Verified steps

1. Identify your ODFI's cut-off times for each of the three Same-Day ACH windows (morning, afternoon, and a third window added in recent years); these cut-offs are set by each Federal Reserve Bank and ACH operator — check current NACHA rules and your bank's documentation for exact times, as they change
2. Set the effective_entry_date in the batch header to the current business day (not tomorrow) for Same-Day ACH; if the file is submitted after the final window cut-off, the effective_entry_date shifts to the next business day
3. Mark the Service Class Code and include the same-day designation required by your ODFI in the batch header; not all ODFI platforms expose this as a separate flag — confirm the required field with your bank
4. Verify that the transaction falls within the per-transaction dollar limit for Same-Day ACH; amounts above the current NACHA limit are not eligible and will be returned as R29 or rejected by the ACH operator — check the current limit in NACHA's rules, as it has been raised multiple times
5. Account for NACHA banking holidays: Same-Day ACH is only available on business days; a holiday causes all windows on that day to be unavailable and the earliest settlement moves to the next business day
6. Reconcile settlement timing by listening for your ODFI's settlement notification or polling your bank account balance; funds are typically available to RDFIs within an hour of the ACH operator settlement but availability to the consumer depends on the RDFI's funds availability policy