What Is the ABA Number?

What Is the ABA Number?
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More often known as a routing number, an American Bankers Association number provides identifying information for your bank, and it's an important piece of information frequently requested for various financial transactions that use your savings or checking account. For example, you'll need to provide the routing number to get started with direct deposit at your employer, link your bank account to financial services and make payments by phone or online from your bank account. Read on to learn more about the purpose of an ABA routing number, steps for finding it and different situations in which you'll need it.

What's an ABA Number?

The ABA developed the routing transit number back in ​1910​ since there needed to be a way to identify the financial institution that's receiving money or paying it to another person or business. Initially, this ​nine-digit code​ only had importance for paper checks before electronic banking systems were invented and used. However, it became increasingly important as electronic transactions like automated clearing house, or ACH, transfers and bank wire transfers become more commonplace. Note that a routing number differs from your checking or savings account number that identifies your specific account at your bank.

The ABA has a set of detailed guidelines that define the policies around routing numbers as well as the process a financial institution needs to go through to get one of these numbers. For example, it collaborates with the National Automated Clearing House Association, Federal Reserve Bank and other entities to develop policies and adapt to the banking system over time. Further, it requires that an institution seeking a routing number must have a Federal Reserve Bank account, and they go through a registrar named Accuity to complete the application process.

Importance of a Routing Number

Without a routing number to easily determine the financial institution involved in a transaction, banks would not be able to operate efficiently. This would cause further delays when sending and receiving funds and could also lead to more transaction errors.

The importance of an ABA routing number means that you need to be extra careful when you provide bank account information so that you don't give the wrong routing number as this can cause payment rejections, fees and other headaches to deal with. Your routing number also needs to be kept safe since thieves could use it if they find out your bank account number as well, and they could complete fraudulent transactions with this information.

Decrypting an ABA Routing Number

When looking at a nine-digit routing number written in magnetic ink at the bottom of your check, you'll find that the ​first eight digits​ have specific meanings for identifying your bank while the last digit is called the check digit and helps identify that you've got an accurate ABA routing number. The ​first four digits​ of your ABA number deal with check processing instructions, and the ​second four digits​ are assigned specifically to identify your financial institution. Take a look at a breakdown of a routing number to get a better picture:

  • Digits 1 and 2​: These numbers must fall within specific ranges from 00 to 80 – with some numbers not yet assigned – to identify the Federal Reserve allocation, and they can identify the type of financial institution or type of financial instrument used. For example, the combination 00 refers to drafts and checks involving a non-federal bank or credit union, while the numbers 01 through 12 identify Federal Reserve districts for governmental financial institutions. The combinations 21 through 32 deal with electronic transfers along with checks involving credit unions assigned up to the year 1985, while numbers 50 through 59 are simply internal routing numbers institutions may use. Digits 61 through 72 are for non-banks that handle electronic transactions, while 80 means it's a traveler's check.
  • Digits 3 and 4​: While digit three will help identify the federal processing center handling the check or transfer, digit four will identify the accompanying Federal Reserve district where that is. In some cases, the fourth digit will be ​0​ when the processing center is in the exact city of the Federal Reserve, while it will be a number ranging from ​one to nine​ if it's outside that city.
  • Digits 5 through 8​: This set of numbers will be a unique identifier for your bank within the Federal Reserve distinct where it's located.
  • Digit 9​: This check digit helps check for a valid routing number, and there's some complex math involved in using this number. Luckily, you shouldn't need to do any calculation yourself since your bank can always help you determine if you've got the right routing number, and there are plenty of online resources to consult.

Finding ABA Numbers by Check

If you've got a checking account and some checks on hand, the easiest way to find the routing transit number for your financial institution is to look at the bottom of the check. You'll see ​three sets​ of numbers, and starting from the left side, these will indicate your routing number, account number and check number, respectively. If you have a savings account or lack any checks to refer to for your checking account, you'll need to use one of the other methods to get your ABA number.

Citizens Bank warns about some potential confusion that can happen with routing numbers in your checkbook. When looking for a check, you might instead come across deposit slips that show what looks similar to a routing number alongside your bank account. Never use that number since it's instead just a code that the bank will use internally. Thus, it won't help you if you need to provide the routing number for a direct deposit, wire transfer or another purpose.

Finding ABA Numbers Through Bank

Banks will often have a page in the resources part of their website that lists information about routing numbers alongside a list of routing numbers that correspond to a particular location or account number. For example, U.S. Bank has a table by state and clarifies that some states have as many as four different routing numbers for specific cities or regions. Huntington Bank has you first get your account number and then provides a list of routing numbers that correlate with the third and fourth digits of the account number. If your bank is small, your job may be much easier as the bank may just have one routing number listed to use.

If you have an online banking account, you can often get both your routing number and account number by looking at your account information through the bank's app or website. Look for an option to see account numbers or an account summary in general. You may need to click a button to show the numbers as banks like Huntington hide them by default for your security.

If these options fail, you can try to call the bank, visit a branch or send a secure email to ask for your routing number. Your financial institution might also have an online chat feature to get the information from a representative. Further, you can always do a simple web search as many financial sites will post routing numbers for popular banks.

Using the Official ABA Tool

Whether you had no luck finding your routing number using the discussed methods or you just want to verify the number to ensure it's correct, the ABA has created a lookup tool on its website that helps you find registered routing numbers. This tool has limitations in that it will only let you look up ​two​ routing numbers a day, and it has an additional limit of ​10​ each month. However, this shouldn't create an issue when you just need to get the routing number for a single bank.

To get started with this tool, you can visit the ABA website, select the "About Us" menu and find an option for "ABA Routing Number." You'll then find a button that reads "Visit the Online Lookup" that takes you to a page where you'll be asked to read the terms of use agreement and select that you agree to those. You can then click "Continue" to see two options for either verifying a routing number you already know or searching for the routing number using bank information using these steps:

  • Verifying routing number​: You can simply enter the number in the "ABA Routing Number" box, complete the CAPTCHA and click "Search" to make sure it's valid and in the registry.
  • Looking up unknown routing number​: At a minimum, type your bank's name in the "Financial Institution Name" box and select its state from the "State" menu. You can also put your bank's city and zip code in case your bank has multiple routing numbers in the state. After you complete the CAPTCHA, click "Search" to see routing numbers found for your bank.

Common ABA Number Uses

Now that you understand what a routing number means and how to find yours, it helps to know when you'd need to hand over this number in everyday financial transactions. While you won't need to worry about it when writing a check that already shows the number, you can expect to provide both your routing and account numbers in these situations:

  • Paying bills online​: Whether you're dealing with utility bills, mortgage payments, student loans, insurance premiums or even tax bills, there's a good chance you can provide your ABA number and account number to pay those electronically. Along with paying through the company or lender's website, you can often initiate the bill payment directly from your bank's website or app. To make things even easier, you can automate your payments.
  • Getting income directly deposited​: With the majority of workers opting to use direct deposit for the conveniences it provides, there's a very good chance you have or will provide your bank routing number for this purpose. Your bank or employer usually gives you a form to put banking details, or you might input this into a company portal or payroll processor website.
  • Signing up for online financial services​: If you use PayPal, Venmo or some other platform that allows you to receive and spend money, a common step is adding a checking or savings account and providing the banking details involved.
  • Receiving your tax refund​: You can get your tax refund more quickly when you tell the IRS you want it deposited into your account and include your ABA number and account number.
  • Buying goods and services through your bank account​: Some retailers let you pay for items using a bank account rather than a credit or debit card. You can do this indirectly using a service like PayPal, but other retailers such as Amazon allow for ACH payments as long as you're in the U.S. and have a current checking account.
  • Participating in wire transfers​: In the case of wiring money to another person through your bank, you'd need to know the account and ABA numbers for the person receiving those funds alongside your own banking information.

You've now got a lot of knowledge about ABA numbers and are ready to use yours for various financial transactions. In any case, always make sure you have the right routing and account numbers and don't provide this information unless you fully trust the party requesting it. Also, contact your bank if you suspect any fraud with your account information.