An ACH number is a nine-digit code that identifies your bank or credit union within the ACH network, which moves money electronically between accounts.
The ACH network is the system the U.S. banking system uses to move money from one account to another without a check or wire transfer. ACH stands for Automated Clearing House. When you set up direct deposit, pay a bill online, or send money to someone else's account, that transaction moves through the ACH network. Your bank's ACH number — also called a routing number — tells the ACH network which bank holds your account and where to send or pull the money.
The ACH number is not the same as your account number. Your account number identifies your specific account at that bank. The ACH number identifies the bank itself. You need both pieces of information to move money in or out of your account electronically.
Key Takeaways
- An ACH number is a nine-digit routing number that identifies your specific bank or credit union within the ACH electronic payment network.
- You will need your ACH number and account number together whenever you set up direct deposit, pay bills online, or authorize someone else to move money from your account.
- Your ACH number appears on the bottom left of your checks, and you can also find it on your bank's website or by calling the bank directly.
- The ACH network processes millions of transactions daily and typically takes one to two business days to complete a transfer.
Where to find your ACH number
The easiest place to find your ACH number is on a check from your account. Look at the bottom left corner of the check. You will see three sets of numbers separated by colons or special symbols. The first set of nine digits is your ACH number (also printed as a routing number). The second set is your account number.
If you do not have checks, log into your bank's website or mobile app. Most banks display the routing number in the account details section, sometimes labeled "routing number," "transit number," or "bank routing code." You can also call your bank's customer service line and ask for the routing number associated with your account. Have your account number ready when you call.
Different branches of the same bank may have different ACH numbers. If you opened your account at a specific branch location, make sure you are using the routing number for that branch, not the main bank number. Your bank's website will show you which routing number applies to your account.
How ACH transfers work
When you initiate an ACH transfer — whether you are receiving a paycheck through direct deposit or paying a bill online — you provide your bank with the recipient's bank ACH number and account number. Your bank sends this information to the ACH network, which is operated by two clearing houses: the Federal Reserve and The Clearing House.
The ACH network batches these transactions together and processes them in cycles. Most ACH transfers take one to two business days to complete. This is slower than a wire transfer (which can happen the same day) but cheaper and more secure for routine payments. The ACH network processes hundreds of millions of transactions every year.
Your bank uses your ACH number to route outgoing money to the correct destination bank. When money comes into your account, the sending bank uses your ACH number to make sure the payment reaches your bank, not someone else's.
ACH number versus account number
These two numbers work together but serve different purposes. Your ACH number (routing number) identifies your bank. Your account number identifies your specific account within that bank. Think of it like an address: the ACH number is the city and state, and the account number is the street address and house number.
When you give someone your banking information to send you money, you must provide both numbers. If you give only the ACH number, the money will reach your bank but not your account. If you give only the account number, the receiving bank will not know which bank to send the money to.
When you need to provide your ACH number
You will need to share your ACH number and account number in several common situations. Direct deposit from an employer requires both numbers so your paycheck reaches the right account. Online bill pay through your bank or a biller's website needs both numbers to pull money from your account. If you are sending money to someone else's account through your bank's transfer service, you need their ACH number and account number.
Third-party payment services — like PayPal, Venmo, or Square Cash — may ask for your ACH number and account number to link your bank account. Mortgage lenders, insurance companies, and loan servicers often ask for this information to set up automatic payments. Always verify you are providing this information to a legitimate organization before sharing it.
Security and ACH fraud
Your ACH number is not secret information — it appears on every check you write and is publicly available through your bank. However, you should still be cautious about who you give your full banking information to. Sharing your ACH number and account number with the wrong person could allow them to set up unauthorized transfers from your account.
If you notice a transfer you did not authorize, contact your bank immediately. Federal law protects you against unauthorized ACH transfers, and your bank can reverse fraudulent transactions. The sooner you report the problem, the faster your bank can investigate and return your money.
Only provide your ACH number and account number to organizations you trust. Legitimate businesses will not ask for this information via email or text message. If you receive an unsolicited request for your banking details, do not respond — contact the organization directly using a phone number or website you know is real.
ACH number variations by account type
Most checking and savings accounts use the same ACH number for the bank or credit union where you hold the account. However, some banks maintain separate routing numbers for different types of transactions or different regions. Money market accounts, investment accounts, and business accounts may have different routing numbers than your personal checking account.
If you have multiple accounts at the same bank, check your statements or online banking to confirm which routing number applies to each account. Using the wrong routing number could delay your transfer or send money to the wrong place. When in doubt, call your bank and confirm the correct routing number for the specific account you want to use.
Frequently Asked Questions
Is my ACH number the same as my bank's main routing number?
Not always. Large banks may have different routing numbers for different branches or regions. Your ACH number is specific to the branch or location where your account is held. Check your checks or bank statement to find the routing number for your specific account, rather than using the bank's main number.
Can someone steal money from my account if they know my ACH number?
They would need both your ACH number and your account number to set up a transfer. Even with both, most banks require additional verification before processing transfers. If you notice unauthorized activity, contact your bank right away — federal law limits your liability for fraudulent ACH transfers.
Do I need a different ACH number for each account I have?
Not necessarily. If you have a checking and savings account at the same bank branch, they may share the same ACH number. However, some banks assign different routing numbers to different account types. Check your statements or bank website to confirm the correct routing number for each account.
What happens if I give someone the wrong ACH number?
The transfer will likely fail or be rejected by the ACH network because the routing number will not match any valid bank. The sending bank will usually return the money to the sender within one to two business days. Double-check the routing number before you initiate any transfer.
Can I use my ACH number to receive money from anyone?
Yes. Your ACH number and account number are all someone needs to send you money through the ACH network. This is how direct deposit works and how you can receive payments from other people or organizations. You do not need to do anything special to receive ACH transfers — your account is set up to receive them automatically.