Every bank requires two key pieces of information to identify customers: the routing number and the account number. Whether you need to set up a direct deposit, such as your paycheck, or order checks online, you’ll need both your bank’s routing number and your personal account number for those transactions.

Account numbers are a lot like a customer ID, or fingerprint, that’s specific to each account holder. Similarly, routing numbers identify each banking institution with a unique numerical ID. Routing and account numbers are assigned to indicate exactly where transactional funds are coming from and going to. Anytime you make an electronic funds transfer, for instance, both the routing and account numbers must be provided to the relevant financial institutions.

Routing Number

The routing number (sometimes referred to as an ABA) is a sequence of nine digits used by banks to identify specific financial institutions within the Unites States. This number proves that the bank is a federal- or state-chartered institution and that it maintains an account with the Federal Reserve

Small banks generally possess just one routing number, while large multinational banks can have several different ones, usually based on the state in which you hold the account. Routing numbers are most commonly required when reordering checks, for payment of consumer bills, to establish a direct deposit (such as a paycheck) or for tax payments. The routing numbers used for domestic and international wire transfers are not the same as those listed on your checks. However, they can easily be obtained online or by contacting your bank. 

Account Number

The account number works in conjunction with the routing number. While the latter identifies the name of the financial institution,  the account number – usually between eight and 10 digits – identifies your individual account. If you hold two accounts at the same bank, the routing numbers will, in most cases, be the same, but your account numbers will be different. 

Your account number is required for every conceivable banking transaction, whether within the bank where the account is held or between banking institutions. Anyone can locate a bank’s routing number, but your account number is unique to you, so it’s important to guard it, just as you would your Social Security Number or pin code. 

Where Are They Located?

You should be able to find both your routing number and account number by logging into your online banking account. You can also find them in your checkbook. At the bottom of each check you will see three groups of numbers: routing numbers (again, typically nine digits) appear as the first group, the account number generally comes second and the third is the actual check number. Sometimes, however, such as on official bank checks, those numbers can appear in a different sequence. 

This series of numbers is embedded with magnetic ink, known as your check’s MICR line (Magnetic Ink Character Recognition). Pronounced “micker,” the magnetic ink enables each bank’s processing equipment to read and process the account information.

The Bottom Line

Account and routing numbers work together to identify your account and ensure that your money ends up in the right place. Both numbers are required to complete many basic banking transactions; it’s important to understand what they are and where to find them.

If you’re ever unsure about which is which, contact your banking institution and always remember to double-check both numbers whenever you provide them to another party. This will ensure a seamless transaction that avoids delays or any associated bank charges stemming from the funds ending up in an incorrect account.