The basics: what ACH requires from you
To send an ACH payment, you need the recipient's bank account number, routing number, and full name. You also need to know whether the account is checking or savings. That's the minimum. Your own bank will handle the rest—they'll format the request, send it through the ACH network, and track it on their end.
The routing number is a nine-digit code that identifies the recipient's bank. The account number is unique to that person's account at that bank. Both are printed on a check, or you can ask the recipient directly. Never guess or use a number from an old check if the recipient has changed banks.
You'll also need to decide how much to send and when. ACH transfers take one to three business days, so if someone needs money today, ACH won't work—you'd need a wire transfer or a real-time payment system instead.
Key Takeaways
- You must have the recipient's routing number, account number, account type (checking or savings), and full name before you initiate an ACH transfer.
- ACH transfers take one to three business days to arrive, so plan ahead if the recipient needs the money by a specific date.
- Your bank will not send the money if the routing number or account number is wrong, and the transfer will bounce back to you.
- You can send ACH payments through your bank's website, mobile app, or by calling customer service, depending on your bank's options.
- ACH transfers are cheaper than wire transfers and safer than sending cash, but they are not instant.
Where to find routing and account numbers
The easiest source is a check from the recipient's account. The routing number appears at the bottom left (a nine-digit code), and the account number is to its right. If the recipient doesn't have a check or you don't want to ask for one, call their bank directly and ask for the routing number—banks give this out freely because it's public information.
Online banking also works. If the recipient has access to their bank's website or app, they can find both numbers in the account details or settings section. Some banks label it "account information" or "bank details." The recipient can screenshot it and send it to you, or simply read the numbers aloud.
Do not use a routing number from an old check if the recipient has changed banks. Banks merge, close branches, and reorganize routing numbers. Ask for a current number or verify it on the recipient's current bank's website.
Information you must provide to your bank
When you initiate an ACH transfer through your bank, you'll enter the recipient's name exactly as it appears on their account. Middle initials, suffixes, and spelling matter—if the name doesn't match, the transfer may be rejected or delayed. Ask the recipient to spell their name as it appears on their bank account if you're unsure.
You'll also specify the transfer amount and the date you want it sent. Most banks let you schedule ACH transfers for a future date, which is useful if you're paying a bill on a specific day. The transfer will process on that date, though it may take one to three business days to arrive.
Some banks ask for a memo or description—this is optional and only appears in your own records, not the recipient's. You might write "rent" or "loan payment" for your own tracking.
What your bank needs from you
Your bank will verify that you have sufficient funds in your account before sending the transfer. If you don't, the transfer will be rejected. Some banks allow overdrafts and will charge a fee; others will simply decline the transfer. Check your account balance before you initiate the payment.
You'll also need to be logged into your bank account or have your account number and PIN ready if you're calling. If you're using your bank's app or website, you're already authenticated. If you're calling customer service, they'll ask security questions to confirm your identity before processing the transfer.
Your bank may also require that you've set up the recipient as a payee before sending money. This is a one-time step that takes a few minutes and adds a small layer of fraud protection. After that, you can send money to that payee as often as you need.
Documents and proof you may need later
Keep a record of every ACH transfer you send. Your bank's website or app will show a confirmation number, the date sent, the amount, and the recipient's name and account number. Screenshot or print this for your records, especially if the transfer is for a bill payment or loan.
If the recipient claims they never received the money, you'll need this confirmation to prove you sent it. You can also contact your bank and ask them to trace the transfer—they can tell you whether it arrived at the recipient's bank and, if not, where it stopped.
For tax purposes, if you're sending money to a contractor or business, you may need to report the transfer on your taxes. Keep records of the date, amount, and recipient's name and tax ID (if applicable). Your bank's statements will show this information, but it's easier to keep a separate file.
Common reasons ACH transfers fail or bounce back
The most common reason is a wrong routing number or account number. If either is incorrect, the receiving bank will reject the transfer and send it back to your bank. Your bank will then return the money to your account, usually within one to three business days. You'll see a notation like "returned" or "rejected" in your transaction history.
A mismatch between the recipient's name and the name on the account can also cause a rejection, though many banks are lenient about middle initials and minor spelling differences. If the first and last names don't match, the transfer is more likely to bounce.
Insufficient funds in your account will cause the transfer to fail before it even leaves your bank. The recipient won't see any attempt to pay them. If you scheduled the transfer for a future date and your balance drops below the transfer amount by then, the transfer will be rejected on that date.
What happens if you send money to the wrong account
If you send an ACH transfer to the wrong account by mistake, the money will arrive at that account, not the intended recipient's. The receiving bank will not stop it or ask questions—ACH transfers are treated as authorized payments once they're sent. You cannot simply cancel an ACH transfer after it's been initiated, though you can try to contact your bank immediately to see if they can recall it before it settles.
If the transfer has already settled (usually within one to three business days), you'll need to contact the recipient of the mistaken payment and ask them to return it. This is a civil matter between you and them—your bank cannot force them to send the money back. If they refuse, you may need to pursue a refund through small claims court or your bank's dispute process.
To avoid this, double-check the routing number and account number before you hit send. Read them aloud to the recipient or verify them on their bank's website. A few seconds of verification can save you weeks of trying to recover a misdirected payment.
Frequently Asked Questions
Can I cancel an ACH transfer after I've sent it?
If you catch the mistake within a few hours and the transfer hasn't settled yet, contact your bank immediately and ask them to recall it. Once the transfer settles at the receiving bank (usually one to three business days), you cannot cancel it. You'll need to ask the recipient to return the money voluntarily.
Do I need the recipient's name to match their account exactly?
The name should match closely—first and last names are critical. Middle initials and suffixes are less strict; many banks accept transfers even if they're slightly different. If you're unsure, ask the recipient how their name appears on their account and use that exact spelling.
What if the recipient's bank is closed when the ACH transfer arrives?
ACH transfers process on business days only. If you send a transfer on a Friday evening, it won't leave your bank until Monday. It will then take one to three business days to arrive at the recipient's bank. Weekends and bank holidays don't stop the transfer, but they do extend the timeline.
Can I send an ACH transfer to an international bank account?
No. ACH is a domestic U.S. payment system only. To send money internationally, you'll need a wire transfer, an international money transfer service, or a service like PayPal or Wise. These have different requirements and fees.
What if I don't know the recipient's routing number?
Ask the recipient directly, or call their bank and provide the recipient's name and account number—the bank will give you the routing number. You can also search online for the bank's routing number if you know which bank they use, though it's safer to confirm with the recipient first.