What is NACHA?
Every ACH bank transfer — including the ones you receive when a customer pays an invoice via bank account — is governed by NACHA (the National Automated Clearinghouse Association). Understanding NACHA's rules is essential before you turn on ACH AutoPay for your customers.
The short version
What NACHA actually does
NACHA (now also known as Nacha — stylized lowercase in their own branding) was founded in 1974 and is based in Herndon, Virginia. It's a nonprofit membership organization whose members are banks and credit unions. NACHA writes and enforces the Operating Rules that govern how all ACH transactions are processed, settled, and disputed in the United States.
The ACH network itself (the rails money moves on) is operated by two ACH Operators: the Federal Reserve (FedACH) and EPN (Electronic Payments Network, operated by The Clearing House). NACHA sets the rules; the operators execute the transfers.
In 2023, the ACH network processed 30 billion transactions totaling over $76 trillion. Every direct deposit paycheck, most bill autopays, and virtually all B2B electronic payments in the US flow through this network under NACHA's rules.
The authorization requirement
The most important NACHA rule for businesses accepting ACH payments: you must have authorization before debiting a customer's account. This is non-negotiable and enforced by the banking system, not just on paper.
Authorization can be:
- Written (paper): A signed paper form authorizing recurring debits.
- Electronic (online): A checkbox or acknowledgment on a web form — must record IP address, timestamp, and the authorization language shown to the customer.
- Verbal (phone): Recorded phone call with the customer verbally authorizing the debit — must include specific disclosure language.
The authorization must specify: the merchant name, the customer's bank account, the amount (or how it will be determined), the frequency (one-time or recurring), and the customer's right to revoke at any time.
Return limits and the retry rule
NACHA's retry rule: If an ACH debit returns for NSF (R01) or insufficient funds, you may retry it no more than two additional times within 30 days of the original settlement date. Exceeding this limit can result in fines and processor termination.
NACHA also monitors your return rate. If your unauthorized return rate (R05, R07, R10, R29) exceeds 0.5%, your bank or processor will flag your account. If your overall return rate exceeds 15%, your ACH access can be suspended.
For service businesses, the best way to stay well within these limits is to only enroll customers in ACH AutoPay after they have clearly authorized it — which is exactly what Win!'s enrollment flow is designed to ensure.
Common ACH return codes
When an ACH transaction fails, you receive a return code. Here are the most common ones service businesses encounter:
| Code | Reason | Initiated by |
|---|---|---|
| R01 | Insufficient Funds | RDFI |
| R02 | Account Closed | RDFI |
| R03 | No Account / Unable to Locate | RDFI |
| R04 | Invalid Account Number | RDFI |
| R05 | Improper Debit to Consumer | RDFI |
| R07 | Authorization Revoked | Customer |
| R10 | Customer Advises Not Authorized | Customer |
| R29 | Corporate Customer Revoked Auth | RDFI |
RDFI = Receiving Depository Financial Institution (the customer's bank).
Same-day ACH
NACHA introduced same-day ACH in phases starting in 2016. As of 2024, same-day ACH is available for transactions up to $1 million (raised from $100,000). Transactions submitted before certain daily cutoffs settle the same business day. There is a per-transaction fee (typically $0.05–$0.15) in addition to standard ACH fees.
For service businesses, same-day ACH is most valuable for large project completion payments where you need funds quickly but the customer prefers ACH. Win! does not currently offer same-day ACH — standard 1–3 day settlement applies.
How Win! helps you implement NACHA requirements
You don't need to be a NACHA expert to use ACH AutoPay with Win!. The platform is designed to support the key operational requirements:
- Electronic authorization captured and stored at enrollment — timestamped, with the disclosure language the customer agreed to.
- Retry logic is configured to respect NACHA's two-retry rule — Win! is designed to avoid exceeding the allowed number of retries.
- Return codes are surfaced in the Win! dashboard with plain-English explanations and recommended next steps.
- Customer self-serve portal lets customers revoke ACH authorization at any time, supporting NACHA's revocation requirements.
Related guides
NACHA Operating Rules are updated periodically. This guide reflects publicly available information as of July 2026. Consult your ACH processor or legal counsel for compliance advice specific to your business. "Nacha" and "ACH" are used descriptively; Nacha is an independent organization not affiliated with Win! or WebTechPro.