What Is an ACH Payment and How Does It Work?

An ACH payment is an electronic bank-to-bank transfer sent through the Automated Clearing House Network, the system that moves direct-deposit paychecks, automatic bill payments, and tax refunds between U.S. financial institutions. In 2025, the network handled 35.2 billion payments worth $93 trillion.¹ Standard transfers settle in one to three business days, and same-day processing is available when timing matters.²

How the Network Moves Money

The ACH Network is a nationwide system through which banks and credit unions exchange batches of electronic credit and debit transfers.³ Instead of processing each payment individually as it arrives, the network groups transactions together and runs them through at scheduled intervals during the day. That batch approach is why ACH is so cheap compared to a wire.

Two operators actually run the network: the Federal Reserve Banks, through FedACH, and the privately operated Electronic Payments Network. Both take payment files from banks, sort them, deliver them to receiving banks, and settle the transactions. When a payment crosses between the two operators, the Federal Reserve handles settlement.³

Every participant follows the Nacha Operating Rules, which set uniform standards for data formatting, security, and processing.² Those rules keep the system reliable at the volumes it handles.

Credits and Debits: Two Directions of Money

Every ACH transaction is either a credit or a debit, depending on who starts the movement.

An ACH credit is a push. The sender tells their bank to move funds to someone else. Payroll direct deposit is the classic example: your employer pushes the paycheck into your account. Tax refunds work the same way.³

An ACH debit is a pull. The receiving party reaches into your account and withdraws funds. When you let your mortgage company deduct the monthly payment automatically, that’s an ACH debit. Utility bills and subscription services usually run the same way.³ Because someone else is pulling money out, you have to give authorization before the first debit. That authorization can be written, electronic, or oral, depending on the type of transaction.

Who’s Involved in a Transfer

Four parties touch every ACH transaction:

The Originator is the person or business that starts the payment: an employer running payroll, a company collecting subscription fees, or a person paying a bill online.
The Originating Depository Financial Institution (ODFI) is the Originator’s bank. It formats the instructions into a proper ACH file and transmits it to the operator.³
The Receiving Depository Financial Institution (RDFI) is the Receiver’s bank. It takes the incoming file and either credits or debits the Receiver’s account.³
The Receiver is the person or company on the other end: the employee getting paid, the vendor collecting an invoice payment, or the consumer whose account is being debited.

How Long an ACH Payment Takes

Standard ACH

Standard ACH transactions settle at 8:30 a.m. ET on the next banking day after the file is processed.⁴ In practice, funds usually become available within one to two business days, though weekends and federal holidays push the timeline further. Banks must submit standard files by 5:00 p.m. ET to make the next day’s settlement.

Same-Day ACH

For payments that can’t wait, Same-Day ACH processes and settles within the same business day. Files run through three daily windows, each with its own deadline and settlement time:⁴

First window: files submitted by 10:30 a.m. ET, settled at 1:00 p.m. ET.
Second window: files submitted by 2:45 p.m. ET, settled at 5:00 p.m. ET.
Third window: files submitted by 4:45 p.m. ET, settled at 6:00 p.m. ET.

The per-transaction limit for Same-Day ACH is $1 million.⁵ That ceiling has been in place since March 2022, when it was raised from $100,000. Nacha has proposed raising it again to $10 million, with a potential effective date in 2027.⁶

What ACH Costs, and How It Compares to a Wire

Consumers usually pay nothing for ACH. Your employer doesn’t charge you to receive direct deposit, and most banks don’t charge for incoming transfers. The costs sit on the business side. Businesses that send or accept ACH through a payment processor typically pay 0.2% to 1.25% of the transaction amount, often with a flat fee of $0.25 to $0.60 added. Some processors skip the percentage and charge only a flat per-transaction fee. Compared to the 2% to 3% that credit card networks charge, ACH is substantially cheaper, which is why so many billers offer discounts for paying by bank transfer.

Wire transfers are the main alternative for moving money bank-to-bank, and they behave differently:

Cost: domestic outgoing wires run $10 to $35 at most banks. ACH is free or close to it for consumers.
Speed: standard ACH settles in one to two business days and Same-Day ACH within hours. Wires settle individually, usually the same day.
Reversibility: ACH transactions can be reversed under certain conditions, such as duplicate payments or wrong amounts. Wires generally cannot be reversed once sent, even in cases of fraud.

Wires make sense for large, time-critical payments where finality matters, like a real estate closing. For recurring payments, payroll, and most business-to-business transactions, ACH fits better because of the cost gap and the built-in ability to correct errors.

Standard ACH has no Nacha-imposed dollar cap, but individual banks set their own daily and monthly transfer limits. Those limits vary widely, so check with your institution before you try to move a large sum.

Your Protections If Something Goes Wrong

Federal law gives you strong protections against unauthorized ACH debits through Regulation E, codified at 12 CFR Part 1005.⁷ Your liability depends on how quickly you report the problem:

Report within 2 business days of learning about the unauthorized transfer: liability is capped at $50.⁸
Report after 2 business days but within 60 days of your statement: liability can reach up to $500.⁸
Report after 60 days: you can be held liable for the full amount of any unauthorized transfers that occur after that 60-day window, if the bank can show it could have prevented them had you reported sooner.⁸

When you report an error, your bank must investigate within 10 business days. It can extend the investigation to 45 days, but only if it provisionally credits your account within the initial 10 days while it keeps looking.⁹ The practical takeaway: review your bank statements. The 60-day clock starts when the statement is sent, not when you open it.

When an ACH Payment Fails

Not every ACH transaction goes through. When one fails, the receiving bank sends it back with a return code that explains why. The most common:

R01, Insufficient Funds: the account doesn’t have enough money to cover the debit. This is the most common return code and the one most likely to trigger a fee from your bank.
R02, Account Closed: the account existed at some point but has since been closed.
R03, No Account / Unable to Locate: the account number is structurally valid but doesn’t match any open account at that bank.
R04, Invalid Account Number: the account number format itself is wrong for that financial institution.
R08, Payment Stopped: the account holder placed a stop payment on the transaction.

Returns for codes like R01 through R04 must be transmitted within two banking days.

International Transfers Work Differently

If an ACH payment involves a financial account in another country, it’s classified as an International ACH Transaction and carries extra compliance requirements, including OFAC sanctions screening at multiple points in the chain and additional identifying data on both sender and receiver.¹⁰ International ACH entries are not eligible for Same-Day ACH processing.¹¹

1
Nacha. Total ACH Payment Volume in 2025 Exceeded 42 Billion
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Nacha. The ABCs of ACH
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Federal Reserve Board. Automated Clearinghouse Services
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Federal Reserve Financial Services. FedACH Processing Schedule
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Federal Reserve Financial Services. Same Day ACH Resource Center
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American Bankers Association. Letter to Nacha on the Proposal to Increase the Same Day ACH Dollar Limit to $10 Million
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eCFR. Part 1005 – Electronic Fund Transfers (Regulation E)
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eCFR. 12 CFR 1005.6 – Liability of Consumer for Unauthorized Transfers
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eCFR. 12 CFR 1005.11 – Procedures for Resolving Errors
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Nacha. International ACH Transactions (IAT) Frequently Asked Questions – Corporate Customers
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Nacha. Expanding Same Day ACH