How to Use a Bank Account Number to Identify a Bank

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A bank account number won't get you very far if you're trying to identify the bank where the account is held. You'll need the bank's routing number for that, but it's really very easy to access. You just have to know where to look for it and what to do with it.


A Bank’s Routing Number

The routing number will not only tell you the name of the bank, but also at which of its locations an account was opened. It's nine digits, and it's sometimes referred to as a routing transit number, an ABA number, an ABA routing number or an ABA routing transit number.

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ABA stands for the American Banking Association, which was responsible for first organizing and managing these numbers back in 1910. Accuity has since taken over for the ABA, and the number now accommodates the Federal Reserve System as well.


Together with a bank account number, the routing number indicates which account at which bank location is involved in a specific transaction. It enables transfers of money via ACH or just the simple presentation of a paper check.

The Bank Account Number

A bank account number is just that – an identifying number for an account held by an individual, business or other entity. The routing number identifies the bank or financial institution where the account is held.


This number is typically longer than the routing number by a digit or two. It applies to only one account at a given financial institution. The account number should appear at the bottom of the check to the right of the routing number. The routing number is always the first set of numerals at the bottom left side of a check.

What the Routing Number Means

A single bank can have more than one routing number. In fact, some large institutions have 100 or more. Some are designated for different purposes, such as Fedwire transfers or ACH transfers.


For example, separate U.S. Bank branches have their own numbers depending on their locations. The number for those in Arizona is different from the one for U.S. Banks in Arkansas. The number not only tells you the name of the bank, but the location where the account was opened and is held as well.

Look It Up Online

Routing numbers are a matter of public record, so it's easy enough to track down an institution by its number if you don't have a paper check in hand that carries the name of the bank, or if you're accepting an electronic transfer. You might even have doubts about the legitimacy of a check and want to make sure that the routing number matches the institution that's named on it.


You can simply track the number online. Look up the bank's website if you know the name of the institution and need its routing number. It should be posted on the website. Or you can simply call the bank and ask for the number if you know the bank but not its routing number.

The process works in reverse as well. There are also routing number lookup tools all over the internet, but your best bet might be to use the one provided by the American Bankers Association. The ABA also publishes a key to routing numbers twice each year. You can search on their site for the routing number and find out the name of the bank.