# AI tells a US small business that ACH same-day returns are free and unlimited, ignoring NACHA's per-entry fee of $0.05 and daily limit of $1 million per ODFI

- **ID:** `banking/ach-same-day-return-fees-nacha`
- **Domain:** banking
- **Category:** resource_error
- **Error Code:** `NACHA-SAME-DAY-RETURN-FEE`
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

NACHA's same-day ACH rules impose a per-entry fee of $0.05 (charged to the ODFI) and a daily aggregate limit of $1 million per ODFI for same-day returns; exceeding these results in rejected returns and additional penalties.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| NACHA Operating Rules (2024) | active | — | — |
| ACH Network (Same-Day ACH, launched 2016) | active | — | — |

## Workarounds

1. **Monitor same-day return volume via the ODFI's ACH reporting dashboard (e.g., via an API from the ODFI bank). Example: 'Set up a webhook to alert when daily same-day return count exceeds 20,000 entries (equivalent to $1,000 in fees at $0.05 each) to avoid hitting the $1 million limit'.** (85% success)
   ```
   Monitor same-day return volume via the ODFI's ACH reporting dashboard (e.g., via an API from the ODFI bank). Example: 'Set up a webhook to alert when daily same-day return count exceeds 20,000 entries (equivalent to $1,000 in fees at $0.05 each) to avoid hitting the $1 million limit'.
   ```
2. **If the limit is reached, schedule returns for the next business day using standard ACH (non-same-day) which has no per-entry fee, but accept the 1-2 day delay.** (75% success)
   ```
   If the limit is reached, schedule returns for the next business day using standard ACH (non-same-day) which has no per-entry fee, but accept the 1-2 day delay.
   ```

## Dead Ends

- **Batching multiple returns into a single ACH file to reduce fees** — NACHA charges per entry, not per file; each return is a separate entry, so batching doesn't reduce the fee. The ODFI is still charged $0.05 per return. (50% fail)
- **Assuming the $1 million limit resets daily and ignoring the cumulative effect over the month** — The limit is per ODFI per day, but if the ODFI processes multiple same-day cycles, the aggregate across cycles must not exceed $1 million; exceeding this in one cycle can block all subsequent returns that day. (40% fail)