What Is ACH?

ACH stands for Automated Clearing House. It is the network that carries your paycheque, your electricity bill, your mortgage payment and the transfer you make between two of your own accounts. Most people use it several times a month without ever seeing the name.

The defining characteristic is that it works in batches. Payments are not sent one at a time as they happen; they are gathered up, sorted, and exchanged between banks at fixed points in the day.

Who runs it

Two operators process ACH payments in the United States: FedACH, run by the Federal Reserve, and the Electronic Payments Network, run by The Clearing House. The rules both follow are written by Nacha, an industry association. Your bank connects to one or both; you never choose.

Credits and debits

Every ACH payment is one of two things, and the difference decides who is in control.

• An ACH credit pushes money out. Your employer sends your salary. You push a payment to a credit card. The sender initiates.
• An ACH debit pulls money in. You give a utility your account details and it takes the bill each month. The receiver initiates, with your authorisation on file.

Autopay set up on a company's website is almost always a debit. That matters later, because debits are the ones you can dispute.

How long it takes

Standard ACH settles in one to three business days. The network runs on business days only, so a payment initiated Friday evening begins processing Monday and may not land until Tuesday or Wednesday.

Same-day ACH exists, with a ceiling of $1 million per transaction and several settlement windows during the day. Whether you can use it depends on your bank offering it, which many still do not for consumer transfers.

What you see in your app is also not the same as settlement. Banks routinely show a pending debit the moment you schedule it, and credit a direct deposit a day or two early as a courtesy.

What you need to send one

A routing number and an account number, both printed on the bottom of a check. Nothing else. There is no per-payment code or authentication step in the network itself, which is why an authorised ACH debit is only as safe as the company you gave the numbers to.

When a payment fails

A returned ACH payment comes back with a code. The two you are most likely to meet:

• R01 — insufficient funds. The account did not have the money. Expect a returned-payment fee from both sides.
• R02 / R03 — account closed or not found. Usually stale details after someone switched banks.

Returns take a few days to surface, so a payment that appeared to go through on Monday can fail on Thursday.

Your dispute rights

Regulation E gives consumers a genuine path here, unlike wires or instant payments. If an ACH debit was unauthorised, was for the wrong amount, or continued after you revoked permission, you can dispute it with your bank. The strongest protection runs for 60 days from the statement showing the transaction, so read statements.

Revoking authorisation is done with the company first, in writing, and then with your bank as a stop payment if they ignore you.

Related

Compared against the alternatives: ACH vs wire vs Zelle. The most common use is direct deposit.

The numbers you need are on your check — see routing number and account number.

Common questions

What does ACH stand for?

Automated Clearing House. It is the batch network that carries direct deposits, autopay, and most bank-to-bank transfers in the United States.

How long does an ACH transfer take?

One to three business days for standard ACH. Same-day ACH exists with a $1 million per-transaction limit, but not every bank offers it to consumers.

Is ACH free?

For consumers, usually yes. Banks rarely charge for incoming or outgoing ACH, though some charge for expedited same-day transfers and for returned payments.

Can an ACH payment be reversed?

An unauthorised or incorrect ACH debit can be disputed with your bank under Regulation E, with the strongest rights within 60 days of the statement. A payment you correctly authorised is much harder to undo.

What does an R01 return code mean?

Insufficient funds. The receiving account did not have enough money to cover the debit, and both sides can expect a returned-payment fee.