What Does Automated Clearing House (ACH) Mean?

The Automated Clearing House, usually shortened to ACH, is the electronic network that moves money between U.S. bank accounts in batches rather than one payment at a time.¹ It is how payroll direct deposits reach your checking account, how the utility company pulls your monthly bill, and how the IRS sends your tax refund. In 2025, the network processed over 35.2 billion payments worth roughly $93 trillion. A mix of federal law and private operating rules governs how fast the money moves, who has to authorize it, and what happens when something goes wrong.

Who Runs the ACH Network

Two different kinds of organizations keep ACH running, and it helps to separate them.

Nacha, a nonprofit, writes and enforces the operating rules that every participating bank and credit union must follow.² Those rules cover data formats, timing, and each institution’s responsibilities. Nacha does not touch the payments themselves.

The actual movement of data is handled by two operators: the Federal Reserve’s FedACH service and The Clearing House’s EPN system.¹ When a bank submits a batch of payment instructions, one of these operators sorts the entries and routes them to the correct destination bank.

The Four Parties in an ACH Payment

Every ACH transaction involves four roles:

The Originator starts the transaction. Your employer, for a direct-deposit paycheck.
The Originating Depository Financial Institution (ODFI) is the Originator’s bank. It validates the request and sends it into the network.³
The Receiving Depository Financial Institution (RDFI) is the bank that holds the destination account and applies the entry.
The Receiver is the person or organization whose account is credited or debited. That is you, if a paycheck lands or a bill is pulled.

In a typical payroll run, your employer tells its bank to send wages, an ACH operator routes the instructions to your bank, and the deposit posts to your account.

Credits and Debits

ACH payments go one of two directions. A credit is a push: the Originator sends money to the Receiver’s account. Payroll deposits, tax refunds, and Social Security payments work this way.⁴ A debit is a pull: the Originator withdraws money from the Receiver’s account, which is what happens when your utility company collects your bill.

Each entry also carries a three-letter code identifying the payment type. PPD covers payments between a business and a consumer account, such as a direct-deposit paycheck or a recurring mortgage draft. CCD covers business-to-business payments like vendor invoices.⁵ The code matters because different types carry different authorization and dispute rules.

When ACH Payments Actually Arrive

ACH is a batch system, not a real-time one. Banks gather payment instructions through the day, bundle them, and send the batch to an operator at scheduled intervals.⁴ The operator sorts, delivers, and the receiving bank posts entries to customer accounts.

Settlement follows a predictable schedule. All ACH debits settle in one business day. ACH credits can settle the same day, the next business day, or in two business days at the sender’s option, and cannot be dated more than two business days into the future. About 80 percent of all ACH payments settle within one business day or less.⁶

Same-Day ACH

When faster is needed, Same-Day ACH settles by the end of the current business day. FedACH offers three processing windows with submission deadlines of 10:30 a.m., 2:45 p.m., and 4:45 p.m. Eastern Time, settling at 1:00 p.m., 5:00 p.m., and 6:00 p.m. respectively.⁷ A single Same-Day ACH payment can be up to $1,000,000.⁸

Authorization for Debits

Before a business can pull money from your account, it needs your permission. Nacha rules require consumer debits to be authorized in writing or through a similarly authenticated method, such as clicking “I agree” on a payment form online.⁹ Without valid authorization, the debit is unauthorized, and you can dispute it with your bank.

Nacha rules also require that ACH data transmitted over unsecured networks, including the internet, be encrypted with commercially reasonable technology.¹⁰

Consumer Protections If Something Goes Wrong

The Electronic Fund Transfer Act and its implementing rule, Regulation E (12 CFR Part 1005), set the main consumer protections for ACH activity on personal accounts.

Liability for Unauthorized Transfers

Your exposure for an unauthorized ACH withdrawal depends on how fast you tell your bank. Regulation E creates three tiers:

Report within 2 business days of learning of the loss and your liability is capped at $50, or the amount taken before you reported it, whichever is less.¹¹
Report later but within 60 days of the statement showing the problem and the cap rises to $500.¹¹
Wait more than 60 days and you can be responsible for the full amount of any unauthorized transfers that occur after the window closes.¹¹

Read your statements. Report anything unfamiliar right away.

How Your Bank Must Investigate

When you report an error, the bank must investigate within 10 business days and tell you the result within three business days after that. It can take up to 45 days if it credits your account provisionally for the disputed amount during the first 10 business days, giving you full use of the money while it finishes looking into things.¹² If the bank concludes no error occurred, it can reverse the provisional credit, but it has to explain the finding first.

Stopping a Recurring Payment

If a company has been pulling a recurring ACH debit from your account, you can stop it. Tell your bank at least three business days before the next scheduled withdrawal.¹³ The request can be oral or written. Once honored, the bank must keep blocking payments from that company until you say otherwise.

Business Accounts Do Not Get the Same Protections

Regulation E covers consumer accounts. It does not cover business accounts. If an unauthorized ACH debit hits your company’s checking account, the $50 and $500 liability caps do not apply. Business-to-business ACH credits fall under Article 4A of the Uniform Commercial Code, and debits are governed by the Nacha Operating Rules together with whatever agreement you signed with your bank. For consumer accounts, unauthorized returns can be processed up to 60 calendar days after settlement; for non-consumer accounts, the window for the receiving bank to return an improper reversal is just two banking days.¹⁴ If you run a business, read the account agreement carefully.

When an ACH Payment Can Be Reversed

If an Originator sends a payment in error, Nacha rules allow a reversal, but only under narrow conditions and only within a tight window. The reversal has to reach the receiving bank within five banking days of the original settlement date, and it is limited to specific mistakes:¹⁴

A duplicate entry, where the same payment was sent twice.
A wrong amount.
A wrong receiver, where the money went to the wrong account.
A wrong date, where a debit hit earlier or a credit posted later than intended.

Reversals are not allowed just because the Originator ran out of funds or changed its mind. A reversal sent for any other reason, or after the five-day window, is improper and can be returned by the receiving bank.¹⁴

1
Board of Governors of the Federal Reserve System. Automated Clearinghouse Services
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Nacha. About Us
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Nacha. How ACH Payments Work
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Nacha. How ACH Works
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Nacha. Standard Entry Class Codes
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Nacha. The Significant Majority of ACH Payments Settle in One Business Day or Less
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Federal Reserve Financial Services. FedACH Processing Schedule
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Federal Reserve Financial Services. Same Day ACH Frequently Asked Questions
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Nacha. Meaningful Modernization Becomes Effective Sept. 17, 2021
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Nacha. Understanding the Value of Encryption in the ACH Network
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eCFR. 12 CFR 1005.6 Liability of Consumer for Unauthorized Transfers
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Consumer Financial Protection Bureau. 12 CFR 1005.11 Procedures for Resolving Errors
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Consumer Financial Protection Bureau. 12 CFR 1005.10 Preauthorized Transfers
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Nacha. ACH Network Rules – Reversals and Enforcement