What is an ABA number?

A key component of everyday banking transactions is your ABA or routing number. Whether you are paying a bill online or setting up direct deposit, it’s helpful to know how to access this number. 

What is an ABA Number?

Developed in 1910, by the American Bankers Association, the ABA number, also known as a routing number, is a nine-digit code used to transfer money to and from your account. Whether you’re transferring money, paying a bill online, or receiving a direct deposit you’ll need both your routing and your account number to ensure these transactions are completed.

How they work

aba numbers

Have you ever wondered how an ATM – a machine – can tell what is written on a check and know what to do with the information? ABA numbers are printed using magnetic ink and utilizing a special font, which allows machines like ATMs to read them. 

Each part of your routing number serves a different purpose. 

  • The first four digits represent the bank’s location. 
  • The fifth and sixth digits determine which Federal Reserve bank your transaction will go through. 
  • The seventh number represents the Federal Reserve processing center to which your bank is assigned. 
  • The eighth digit is the Federal Reserve district your bank is located in. 
  • Finally, the ninth digit provides a “checksum,” which is a mathematical equation using the other numbers. If the numbers do not match, the transaction is flagged and processed manually. 

In short, your ABA number gives specific instructions during deposits and withdrawals, making sure your transaction is completed accurately each time you make a transaction.

Where to find these pieces of information

Your routing number is printed on the bottom of paper checks, usually on the bottom left corner. Still not seeing what you need? We’re always here to help.

At Westfield Bank, we make answers and information easy to find. Learn more about our tools and resources like our ABA or routing numbers. For your quick reference, our ABA or routing number (041272279) is located on the bottom of our website or online banking at www.westfield-bank.com as well as on our mobile app.