An Automated Clearing House (ACH) routing number is a nine-digit code that banks and financial institutions use to identify the specific facility responsible for transferring money between accounts within the US. Like a home address, it directs electronic funds transfers (EFTs) to the correct bank and branch. Each bank or credit union has a unique code. You can find it on direct deposit forms, on the bank's online system, or by contacting the bank directly.

ACH routing numbers are necessary for setting up direct deposits, automatic payments, and wire transfers. Businesses that send or receive ACH payments need to know the correct routing number to ensure the funds reach the right bank account. This matters as demand for ACH payments is growing, given that the ACH network moved 8.9 billion payments in the first quarter of 2026 alone.

Below is a guide on ACH routing numbers, including what they are, what they're used for, and how to find one.

What's in this article?

• What is an ACH number?
  
• What are ACH routing numbers used for?
  
• How can you find an ACH routing number?
  
• ABA vs. ACH routing numbers
  
• History of ACH routing numbers
  
• Common mistakes with ACH routing numbers
  
• How Stripe Payments can help
  
• FAQs about ACH routing numbers
  

What is an ACH number?

ACH stands for Automated Clearing House, a network that moves money and information electronically between banks and financial institutions within the United States. An ACH number is a type of routing number used specifically for electronic transactions, such as direct deposits and bill payments.

ACH routing numbers have nine digits, each of which serves a specific purpose. The first two digits indicate the Federal Reserve Bank district where the institution is located. The second pair of digits are the Federal Reserve Bank's district branch – or processing centre – assigned to the bank. The fifth, sixth, seventh and eighth digits represent the institution's unique identifier within its Federal Reserve district. The final digit is a checksum, which is a mathematical sum used to verify that the first eight digits are correct.

What are ACH routing numbers used for?

These nine-digit numbers are used in various ways to direct funds to the correct financial institution. Here are some of the main uses for ACH routing numbers:

• Employers use them to directly deposit employees' salaries into their bank accounts.

• Individuals and businesses use them to set up scheduled payments for loans or bills.

• ACH routing numbers facilitate the transfer of funds between different bank accounts – both personal and business accounts.

• Utility companies rely on them to receive monthly payments from customers.

• They're used to send and receive state and federal tax payments and refunds.

• Businesses and non-profits receive contributions or payments for services rendered via ACH numbers.

In each case, ACH routing numbers help ensure that the correct parties send and receive the funds in an organised, timely manner.

How can you find an ACH routing number?

There are several ways to locate an ACH routing number:

• Check the bottom of a cheque associated with the account. Traditionally, the first set of numbers printed on the left side is the routing number.

• Look at a bank statement. Some banks include the routing number on statements.

• Log in to the financial institution's online banking platform or mobile app. Typically, the routing number is listed in the account information or account settings section.

• Visit the bank's website. Most banks have FAQ sections or dedicated pages where they list their routing numbers.

• Call the bank. A representative can provide the routing number after verifying the account holder's identity.

• Use the routing number lookup tool of the American Bankers Association (ABA). Anyone who needs to find or verify a routing number can access this.

An example of an ACH routing number is 021000322, which Bank of America frequently uses for automatic payments or ACH electronic transactions.

ACH routing numbers can vary based on your region, account type, or transaction type. Some banks use different routing numbers for wire transfers and ACH transactions, while others have multiple numbers for different geographic areas. Always confirm the correct routing number with your bank before you make a transaction, to avoid any errors or delays.

ABA vs ACH routing numbers

While both ABA and ACH routing numbers facilitate payment processing, they're used for different types of transactions.

ABA routing numbers – also known as routing transit numbers – were originally designed to facilitate the sorting, bundling, and shipping of paper cheques. They're still used today for the clearing of physical cheques and for wire transfers. These numbers can be found on the bottom left side of paper cheques.

ACH routing numbers are used only for electronic transfers and payments. For some banks, the ACH and ABA routing numbers are the same, but other banks have separate numbers specifically for ACH transactions. This differentiation helps institutions route the transactions through the correct processing systems, whether they're direct deposits, bill payments, or other automated transfers. Using the wrong number can cause delays or failed transactions. Always check with your bank to confirm the correct number for your specific use case.

Here are the key differences between ABA and ACH routing numbers.

ACH routing number examples

Because major national banks operate across multiple regions, many financial institutions maintain different ACH routing numbers depending on the state where the account was opened. Furthermore, the number a bank uses for electronic transfers is often entirely separate from the code used for wire transfers. Examining how different banks structure their numbers helps clarify why verifying your specific regional code is important.

• Bank of America: Frequently uses 021000322 for accounts opened in New York and 111000025 for those opened in California. Its wire transfer code (026009593) is distinct and cannot be used for ACH payments.

• Chase: Operates with over 24 different routing numbers based on regional jurisdiction. For example, downstate New York accounts typically use 021000021, while California and Nevada accounts use 322271627.

• Wells Fargo: Uses state-specific codes such as 121000248 for California and 091000019 for Pennsylvania. This reflects its broad footprint.

• Citibank: Relies on varying region- and account-type numbers, using codes such as 021000089 for New York operations and 322271724 for West Coast accounts.

History of ACH routing numbers

The system for ACH routing numbers began when the banking industry started to automate and organise the processing of cheques and other financial transactions more effectively in the 20th century. The ABA created the ACH routing number system in 1910 to facilitate the sorting, bundling, and shipment of paper cheques.

As electronic payments increased in popularity, the ACH network was adapted for use in electronically processing funds. The routing number system processed these payments efficiently, allowing institutions to transfer funds without sending paper documents. Over time, ACH transfers have been used for a wide variety of payments services, including direct deposits of paycheques, automatic mortgage and bill payments, and government and business transactions. The ACH network processes large volumes of credit and debit transactions, which include direct deposits as well as direct payments.

The reliability and organised structure of the ACH routing number system have supported the expansion of electronic money transfers and the shift towards a paperless financial system. As the volume of digital transactions continues to rise, routing numbers will continue to be important in daily financial operations.

Common mistakes with ACH routing numbers

Even though ACH routing numbers follow a strict nine-digit format, manual data entry and misunderstandings about how banking networks operate frequently lead to transaction delays, rejections, or misdirected funds.

Avoiding these common pitfalls helps ensure smooth processing for payroll, vendor payments, and recurring bill collection:

• Confusing wire routing numbers with ACH routing numbers: Many of the major financial institutions use entirely distinct codes for electronic ACH transfers and domestic or international wire transfers. Entering a wire routing number for an ACH batch payment will typically cause the transaction to fail.

• Assuming cheque printing matches electronic numbers: Relying solely on the routing number printed on the bottom of a traditional paper cheque can be risky. Some banks maintain separate routing codes specifically for electronic transactions vs. paper cheque clearing.

• Overlooking regional bank variations: National banks often use different routing numbers depending on the specific state or region where the bank account was originally opened. Using a number associated with a different branch region can delay processing.

• Failing to update records after bank mergers: Financial institution mergers and acquisitions frequently result in updated routing numbers or legacy codes. Failing to update your vendor or customer files can lead to rejected payments.

• Treating routing validation as a complete fraud shield: Verifying a valid ACH routing number ensures the funds are directed to the correct financial institution, but it doesn't confirm the recipient's identity. Fraudulent actors can share the exact same routing code, making robust verification necessary.

How Stripe Payments can help

Stripe Payments provides a unified, global payment solution that helps any business – from scaling startups to global enterprises – accept ACH Direct Debits.

Stripe Payments can help you:

• Optimise your checkout experience: Create a frictionless customer experience and save thousands of engineering hours with prebuilt payment UIs and quick ACH Direct Debit integration.

• Expand to the US market faster: Reach US customers from every state and reduce the complexity and cost of multicurrency management when collecting payments in US dollars.

• Simplify ACH mandates: Present customers with a required ACH mandate as part of the payment flow through Stripe Checkout, Stripe's Payment Element, or hosted invoice pages.

• Improve payment performance: Increase revenue with a range of customisable, easy-to-configure payment tools, including a fully hosted flow for collecting bank account details and verifying them with microdeposits.

• Move faster with a flexible, reliable platform for growth: Build on a platform designed to scale with you, with 99.999% historical uptime and industry-leading reliability.

Learn more about how Stripe Payments can power your online and in-person payments or get started today.

FAQs about ACH routing numbers