What is an ABA number & where to find it

United Kingdom By Western Union June 6, 2024

An ABA number is a nine-digit code used to identify financial institutions in the United States.
To send money internationally from the UK to the US, you will need the ABA routing number for the transfer. This code will ensure that the money you are sending arrives at the right bank. Using the correct ABA number reduces the risk of errors in the funds transfer.
This guide explains what the ABA number is, how it works, and how you can locate and use it for transactions involving US banks.

In this article

• What is routing number ABA?
• Where can you find an ABA number?
• How do ABA numbers work?
• How do ABA numbers work for international transfers?
• Is the ABA number the same thing as a routing number?
• What is the difference between ABA and a wire transfer?

What is an ABA number?

An American Bankers Association number, or ABA number, is a nine-digit code that is an identifier for financial institutions in the US. Like how your account number identifies your bank account, the ABA routing number identifies specific banks within the network of US financial institutions.
You will need an ABA number whenever you want to send money to the US, whether you are paying bills or making a wire transfer. The ABA number will direct the electronic transfers to the correct bank and branch.

Where can you find an ABA number?

To send money to a US bank account, you will need the recipient’s name, account number, bank name, and ABA number. Without the correct ABA routing number, there’s a risk that your funds will be misrouted.
You can use these methods to find an ABA number:

Ask the recipient

You can ask the recipient for the ABA number of their bank. The recipient can easily find this number on their bank statements or by logging into their online banking account where it’s often displayed. They can also look in their checkbook as ABA routing numbers are often on the bottom left corner of checks.

Contact the bank

Another way to get the ABA number is to contact the recipient’s bank directly. You can call or email the bank’s customer service. They will provide an accurate ABA number for your transactions.

Check the bank’s website

You can visit the bank’s official website to find the ABA routing number. It is usually listed in the FAQ or help section of the website. This also allows you to confirm the ABA number the recipient sent you.

How do ABA numbers work?

Bank routing ABA numbers guide the funds you are sending to the correct financial institution during the transaction. Let’s say you need to send money to a friend’s bank account in New York. Your friend banks with a specific branch of Bank of America in Manhattan. To ensure the money is sent accurately, you would use Bank of America’s ABA number specific to that branch.
The nine-digit code has a specific structure to simplify the identification of banks, ensuring that payments are processed quickly and accurately. Here is what the nine digits in the ABA number mean:
• First four digits: This is the Federal Reserve Routing Symbol. The first two digits indicate the Federal Reserve Bank district where the bank is located. The third digit indicates the Federal Reserve check processing centre assigned to an institution within a Federal Reserve district. The fourth digit represents the state within the district where the bank is located.
• Next four digits: These are specific to the bank itself. This sequence uniquely identifies the bank within the Federal Reserve’s system.
• Ninth digit: This is the checksum, used to verify the accuracy of the routing number. It is calculated through a specific formula using the first eight digits.

How do ABA numbers work for international transfers?

ABA numbers play a crucial role in international money transfers to the US. Here’s how they work:


To start the transfer, you’ll need to provide the recipient’s ABA number along with other necessary banking details. This number guides the international banking system to the specific bank of your recipient, initiating the transfer process.


Once you initiate the transfer, your bank uses the ABA number to ensure the funds are sent to the right place. This step involves checking the accuracy of the routing information and confirming the legitimacy of the receiving bank.


If the verification is successful, the funds are routed based on the ABA number. This number directs the payment to the appropriate regional Federal Reserve Bank and then to the recipient’s local bank.


Once the funds reach the intended bank, they are processed and deposited into the recipient’s account. To know how long these transfers can take, you can check the bank transfer details for international transfers.

Is the ABA the routing number?

An ABA number is the same as a routing number. It is often referred to as an ABA routing number, US routing number, or Routing Transit Number (RTN). While these different terms can become confusing, they all mean the ABA number.

What is the difference between ABA number and a wire transfer?

An ABA number and a wire transfer have different roles in money transfers. The ABA number is a specific code used to identify banks for routing transactions. A wire transfer is a method of sending money electronically, which often uses the ABA number to direct funds. Essentially, the ABA number acts like an address for the bank while the wire transfer is the actual movement of money between accounts.
For domestic wire transfers in the US, senders will need to provide the ABA number. For international wire transfers to the US, senders will need to provide the ABA number and additional details, such as the SWIFT code. The SWIFT code identifies the foreign bank involved in the transfer.
Some banks may use different ABA numbers for international wire transfers. It’s important to confirm you are using the correct ABA number for any international wire transfers to the US. You can do this by contacting the bank’s customer service or checking the bank’s website.

FAQs for ABA numbers

Do UK banks have an ABA number?

UK banks do not have ABA routing numbers as these are specific to US financial institutions. UK banks utilise sort codes to identify banks and their branches.

Is an ABA the same as a sort code?

No, an ABA number is not the same as a sort code. An ABA number is a nine-digit code to identify banks in the US, while a sort code is a six-digit code to identify banks in the UK.

Is an ABA the same as an account number?

No, an ABA number is not the same as an account number. The ABA number identifies the recipient’s bank during a transaction. The account number specifies the individual account within that bank to where the funds should be sent.

What is the difference between ABA and SWIFT code?

ABA numbers are used for transactions with US banks. SWIFT codes are used for international transactions between banks across different countries.