
- What is an ACH routing number?
- Why do you need an ACH routing number?
- How to find and verify your ACH routing number
- ACH routing numbers vs. other routing numbers
- Common mistakes and how to avoid them
- Simplify your ACH payments with Ramp

ACH routing numbers identify the financial institutions involved in an electronic transfer. Issued by the American Bankers Association, ACH routing numbers play a critical role in how money moves between bank accounts in the United States. Every time you receive a direct deposit, send an online payment, or set up a recurring bill, this number helps ensure the funds reach the right place.
In this guide, we cover what an ACH routing number is, how to find and verify yours, and how to use it correctly in your electronic payment processes.
What is an ACH routing number?
An ACH routing number is a 9-digit code that identifies the bank or credit union processing an Automated Clearing House (ACH) transfer. Each ACH routing number is unique to a specific financial institution. It's designed to handle large volumes of routine business payments, such as direct deposits, employee salaries, or recurring vendor invoices.
Larger banks often have multiple ACH routing numbers due to geographic and service-related factors, like the account's location or the type of transaction being processed. You’ll need to verify the correct routing number for your specific payment to ensure your payments process correctly.
Why do you need an ACH routing number?
An ACH routing number enables banks and payment processors to route funds to the correct institution and account when making or receiving electronic payments. Without it, the ACH network wouldn’t know where to send your money.
Whenever you set up an ACH payment, whether it’s for payroll, paying vendors, or accepting customer payments, you’ll need the correct routing number. Using the wrong number can lead to processing delays, rejected transactions, or even misdirected funds. Taking the time to verify the routing number helps you avoid these errors and keep your payments running smoothly.
How to find and verify your ACH routing number
Most banks display the correct ACH routing number in your online account details, on paper checks, or within your mobile app. But because some banks use different routing numbers for ACH transfers, wire payments, and paper checks, it’s easy to mix them up.
If you need to make or receive ACH payments, here’s how you can locate your ACH number:
- Check your checkbook: On a paper check, the routing number is printed as the first 9-digit number on the bottom-left corner before your account number. The routing number on checks is often different from the one used for ACH payments, so double-check with your bank if you’re unsure.
- Log in to your online banking portal: Most banks display your routing number when you log in to your online bank account or mobile banking app. Look in the account details section of the checking account or savings account you’re using for ACH payments. Some banks have separate routing numbers for different types of transactions, such as ACH, wire transfers, and paper checks.
- Look it up in the Federal Reserve’s online directory: The Federal Reserve maintains a searchable online database of official bank routing numbers. This is a reliable way to cross-check the number you have against what’s officially registered.
- Contact customer service: Contact your bank's customer service if you can’t find your ACH routing number using the above methods. After verifying your identity, ask specifically for the ACH routing number to make sure you’re using the correct one for electronic payments.
ACH routing numbers vs. other routing numbers
While it’s important to understand ACH routing numbers, your accounts payable (AP) team will most likely need to deal with other types of routing numbers, too.
Banks assign different routing numbers for wires, ACH payments, and paper checks because each type of transaction is processed through a separate network. Here are the key differences between them:
Feature | ACH routing numbers | Wire transfer routing numbers | American Bankers Association (ABA) routing numbers |
---|---|---|---|
Use | Electronic payments processed through the ACH network | Domestic and international wire transfers | Paper checks and other non-electronic transactions |
Transaction type | Batch-processed electronic transfers | Real-time, individual transfer of funds | Manual check processing and account identification |
Format | 9 digits long; the first 2 digits typically range from 61 to 72 | 9 digits long; often unique to wire transfers | 9 digits long; the first 2 digits typically range from 00 to 12 |
Processing network | ACH network for batch-processed electronic payments | Wire transfer systems like SWIFT or Fedwire for real-time transfers | Check-clearing systems managed by Federal Reserve Banks or private clearinghouses |
Processing speed | Typically 1–2 business days | Same-day or next-day (often within hours) | Varies depending on the clearing process |
Typical cost to business | Low or no fee | Higher fees (varies by bank) | Usually no fee unless special handling required |
Used by | Employers, billers, online platforms, AP teams | Corporate finance, international businesses, treasury departments | Individuals, small businesses, legacy systems |
You may also hear terms like bank routing number or routing transit number; these are just different names for the same 9-digit ABA number assigned to your financial institution. Note that this isn't your account number, which is unique to your personal or business account.
Common mistakes and how to avoid them
There are several ways your business could make mistakes with ACH routing numbers. Understanding the most common pitfalls can help you avoid those mistakes as well as their repercussions.
Entering incorrect routing numbers
One of the most common mistakes in an ACH transaction is inputting the wrong ACH routing number, whether due to simple input error or misreading the number from a document. This sends payments to the wrong financial institution, causing delays or failed ACH transactions.
Make sure you double-check routing numbers against your bank’s official website or account statements.
Using the wrong routing number for the transaction type
ACH routing numbers are assigned for specific electronic payment purposes, and using the wrong one can result in transaction errors. For example, using a domestic ACH routing number for an international payment instead of a SWIFT code will cause the transaction to fail. Rather than assuming the number on a paper check is correct for ACH, confirm with your bank.
Using outdated routing numbers
Routing numbers can change due to bank mergers, acquisitions, or operational updates, but businesses often fail to update their records. This can result in payments being sent to invalid or outdated routing numbers, causing returns and delays that impact cash flow. Make sure to promptly update your records after any bank mergers or account changes.
Misinterpreting numbers on documents
The numbers printed on bank documentation can be confusing, and businesses sometimes mistake account numbers or other identifiers for ACH routing numbers. This leads to incorrect data entry, resulting in rejected or misdirected transactions. Clearly separate account numbers and routing numbers when entering payment details.
Failing to verify routing numbers
Skipping the step of verifying ACH routing numbers before initiating transactions is a common error that increases the likelihood of failed transactions. To ensure accuracy, consider using AP automation software to validate routing numbers before sending payment.
Skipping authorization from clients or vendors
Another frequent mistake is using ACH routing numbers without proper authorization from the client, employee, or vendor. This can lead to disputes, legal issues, and loss of stakeholder trust. Before initiating ACH payments, make sure you get written authorization from vendors, employees, or clients.
Neglecting security for ACH routing numbers
Some businesses fail to implement adequate security measures for handling ACH routing numbers. This exposes sensitive information to unauthorized access and increases the risk of ACH fraud, data breaches, and financial losses. By staying compliant with Nacha regulations and using automated verification tools, you can minimize errors in your payment processes.
Simplify your ACH payments with Ramp
Repeatedly tracking down the same routing numbers and manually filling out forms can slow down your AP team. With Ramp’s accounts payable software, you can automate your entire AP process and easily scan or upload invoices, receipts, vendor onboarding documents, purchase orders, and more.
We offer AI-powered automated approval workflows, 2-way and 3-way invoice matching, and complete visibility into the payment cycle across all vendors and payment methods, including ACH, checks, cards, and international wires.
See everything Ramp can do for your AP team with a free interactive product tour.
This post includes general information about ACH payments. For help with ACH functionality specific to Ramp, visit Ramp Support for more details.

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