An ACH number is the combination of your bank’s nine-digit routing number and your account number, and together those two figures are what an employer, biller, or transfer service needs to move money into or out of your account through the Automated Clearing House network. You’ll find both printed along the bottom of a paper check and listed inside your online or mobile banking under account or direct deposit details. The ACH network handled $93 trillion across more than 35 billion transactions in 2025, so these are the numbers behind most of the everyday electronic payments you send and receive.1Nacha. ACH Network Volume and Value Statistics
The Two Numbers That Make One ACH Number
An ACH payment needs two pieces of information to reach the right place, and both have to be correct.2Nacha. ACH File Details
- The routing number is nine digits and identifies your bank. It’s the same for every customer at that institution (or at that branch group, for larger banks).
- The account number identifies your specific checking or savings account. Length varies from one bank to another.
The routing number gets the payment to your bank; the account number gets it to you. Miss either one, or use the wrong type of routing number, and the transaction fails.
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, and the last short group is just the check number, which you can ignore. If you see a single extra digit sitting to the left of the routing number, that’s an external processing code used by check processors and is not part of either number.
In Your Online or Mobile Banking
If you don’t keep paper checks, sign in to your bank’s website or app and open the account you want to use. Look for a section labeled something like “account details” or “direct deposit information.” Both numbers will be listed there, and most banks let you copy them, download a pre-filled direct deposit form, or share them straight from the app.
By Asking Your Bank
You can also call your bank or visit a branch. The routing number is public information; the account number is not, so expect to verify your identity before a representative reads it back to you.
Verifying a Routing Number Someone Gave You
When someone else sends you routing information and you want to confirm it’s real before you send money, the Federal Reserve publishes an E-Payments Routing Directory that will tell you whether a routing number is valid and which institution owns it.3Federal Reserve Financial Services. E-Payments Routing Directory A valid routing number is always exactly nine digits; anything longer or shorter isn’t one.4Cornell Law School. 12 CFR Appendix A to Part 229 – Routing Number Guide to Next-Day Availability Checks and Local Checks
Confirming an Account Through Micro-Deposits
When you connect your bank to a new payment platform, the service may send one or two small deposits under $1.00 to your account and ask you to confirm the exact amounts. That proves you actually own the account tied to the numbers you entered. Nacha requires these test deposits to carry the label “ACCTVERIFY” so they’re easy to identify on your statement.5Nacha. Micro-Entries (Phase 1)
ACH Routing Number vs. Wire Routing Number
Many banks use different routing numbers for ACH and for wire transfers, because the two payment systems run on different networks. A wire routing number will not work for an ACH payment, and an ACH routing number will not work for a wire. If you enter the wrong one, the transaction will typically be rejected or returned.
When you look up your numbers, pay attention to the label. If the section is headed “ACH” or “direct deposit,” you’re in the right place. If it says “wire transfers” or “international wires,” that’s a different number. This is the single most common reason a correctly typed routing number still fails.
What You’ll Use Your ACH Number For
Most routine electronic payments run on ACH:
- Direct deposit of your paycheck. Your employer uses your routing and account numbers to deposit wages on payday.
- Recurring bill payments. Utilities, lenders, insurers, and subscription services pull payments directly from your account when you enroll in autopay.
- Bank-to-bank transfers. Moving money between accounts at different institutions is done by providing each side’s routing and account numbers.
- Government payments. Tax refunds, Social Security benefits, and other federal payments are usually delivered by ACH.
Standard ACH transfers settle in one to three business days, since transactions are collected into batches and processed at scheduled intervals rather than moved in real time.6Federal Reserve Financial Services. FedACH Processing Schedule Weekends and federal holidays don’t count as business days, so a Friday-afternoon transfer often lands the following week.
Keeping Your ACH Number Safe
Your routing and account numbers together are enough for someone to attempt to debit your account, so treat them like the sensitive financial data they are. The ACH network itself is secure, but fraud tends to exploit how people share and store account information: phishing, spoofed emails, account takeover, and social engineering.7Nacha. Current Fraud Threats
- Share your numbers only with employers, established billers, and institutions you already have a relationship with. Be skeptical of any request that arrives by email or text.
- Review your bank statements regularly, or turn on transaction alerts so you see every debit as it posts.
- If you spot something you didn’t authorize, report it to your bank right away.
Federal Regulation E limits your liability for unauthorized electronic debits, and how much you can lose depends on how quickly you report the problem. Notify your bank within two business days and your liability is capped at $50. Wait longer than that but report within 60 days of the statement showing the transfer, and it can rise to $500. Wait past 60 days and you could be on the hook for the full amount of any further unauthorized transfers the bank can show would have been prevented by earlier notice.8eCFR. 12 CFR 1005.6 – Liability of Consumer for Unauthorized Transfers Once you report a problem, the bank has 10 business days to investigate, or it must provisionally credit your account while it keeps looking, for up to 45 days total.9eCFR. 12 CFR Part 1005 – Electronic Fund Transfers (Regulation E)
The practical rule is simple. Check your statements often, and if a debit looks wrong, call your bank the same day.