An ACH number is the combination of your bank’s nine-digit routing number and your account number, used together to send and receive electronic payments through the Automated Clearing House network. The routing number identifies your bank. The account number identifies your specific account inside that bank. You need both for any ACH transaction to reach the right place. In 2025, the ACH network moved $93 trillion across more than 35 billion transactions, which covers most direct deposits, bill payments, and bank-to-bank transfers in the United States.1Nacha. ACH Network Volume and Value Statistics
The Two Numbers That Make Up an ACH Number
Both pieces are required, and they do different jobs.2Nacha. ACH File Details
- The routing number is always nine digits and identifies your financial institution. Think of it as the street address for your bank.
- The account number identifies your individual checking or savings account. Its length varies by bank. Think of it as the apartment number inside that building.
Give someone just one of these and the payment has nowhere to go. Give them both, and the ACH network can deliver.
Where to Find Your ACH Number
On a Paper Check
Look at the bottom of a personal check. Reading left to right, the first group of nine digits is your routing number. The next group is your account number. The final short group is the check number and is not part of your ACH information. Some checks print an extra single digit to the left of the routing number; that’s an external processing code used by check processors and should be ignored.
In Online or Mobile Banking
If you don’t have checks, sign in to your bank’s website or app and open the account you want to use. Look for a section called “account details,” “direct deposit information,” or something similar. Selecting the specific checking or savings account will display both numbers. Most banks also let you download a pre-filled direct deposit form or share the details directly from the app.
Verifying a Routing Number
If someone has given you a routing number and you want to confirm it before sending money, the Federal Reserve runs an official E-Payments Routing Directory that will tell you whether the number is valid and which institution it belongs to.3Federal Reserve Financial Services. E-Payments Routing Directory A routing number with more or fewer than nine digits is not valid and the transaction will be rejected.
Confirming an Account Through Micro-Deposits
When you link your bank to a new payment service, the service often sends one or two tiny deposits of less than $1.00 each to your account. You then enter the exact amounts back into the service to prove the account is yours. Nacha requires these deposits to be labeled “ACCTVERIFY” so banks can tell them apart from ordinary payments.4Nacha. Micro-Entries (Phase 1) Once you confirm the amounts, the service can process ACH payments using your routing and account numbers.
ACH Routing Numbers Are Not Wire Routing Numbers
Many banks publish two different routing numbers: one for ACH and direct deposit, another for wire transfers. The two systems run on separate networks, and the numbers are not interchangeable. If you give a wire routing number for an ACH setup, the transaction will typically fail or be returned. When your bank’s website lists its routing numbers, use the one explicitly labeled for ACH or direct deposit.
What Your ACH Number Is Used For
Most routine electronic payments rely on these two numbers:
- Direct deposit of paychecks, so your employer can deposit wages electronically on each pay date.
- Automatic bill payments pulled by utilities, lenders, insurers, and subscription services.
- Transfers you initiate between accounts at different banks.
- Government payments such as tax refunds and Social Security benefits.
How Long an ACH Payment Takes
Standard ACH transfers typically settle in one to three business days. Money doesn’t move instantly; transactions are gathered into batches and processed at scheduled intervals during the day.5Federal Reserve Financial Services. FedACH Processing Schedule
Same-day ACH is also available, with four daily submission windows. The earliest deadline is 10:30 a.m. ET and the latest is 6:00 p.m. ET. A single same-day ACH payment can’t exceed $1 million. Anything submitted after the final window or above that limit falls back to the standard one-to-three-day timeline.6Federal Reserve Financial Services. Same Day ACH Frequently Asked Questions
Weekends and federal holidays don’t count as business days. A payment started Friday afternoon may not land until the following Monday or Tuesday.
Keeping Your ACH Information Safe
Your routing and account numbers are sensitive. Someone who has both can potentially initiate an ACH debit from your account. The ACH network itself is secure; most fraud exploits how people and businesses handle the numbers, through phishing emails, business email compromise, account takeovers, and social engineering.7Nacha. Current Fraud Threats
A few habits reduce your exposure:
- Only share your ACH numbers with employers, established businesses, and institutions you trust. Avoid sending them over email or text when you can.
- Read your statements regularly. The sooner you spot an unauthorized debit, the lower your potential liability.
- Turn on transaction alerts in your bank’s app so you see every debit as it happens.
If an Unauthorized ACH Payment Hits Your Account
Federal law caps how much you can lose when someone pulls an ACH payment from your account without permission. Under Regulation E, your liability depends on how fast you tell your bank:8eCFR. 12 CFR 1005.6 – Liability of Consumer for Unauthorized Transfers
- Report within two business days of learning about the problem, and your liability is capped at $50 or the amount of the unauthorized transfers before you reported, whichever is less.
- Report after two business days but within 60 days of the statement showing the problem, and liability can rise to $500 for transfers the bank can show would not have happened if you had reported sooner.
- Wait more than 60 days after the statement, and you could be responsible for the full amount of unauthorized transfers that occur after that 60-day window, if the bank can show timely notice would have stopped them.
Once you report the problem, your bank has 10 business days to investigate. If it needs longer, it must provisionally credit your account while it keeps looking, up to a total of 45 days.9eCFR. 12 CFR Part 1005 – Electronic Fund Transfers (Regulation E) Check your statements, and report anything you don’t recognize as soon as you see it.