# Routing Transit Number Explained: Find Yours and Understand Its Use

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## What Is a Routing Transit Number?

A routing transit number (RTN) is a nine-digit number used to identify a bank or [financial institution](https://www.investopedia.com/terms/f/financialinstitution.asp) when clearing funds for electronic transfers or processing checks in the U.S. Routing numbers are used in online banking and by clearinghouses for transactions. They're critical to the operations of online banking and clearinghouses.

Only banks eligible to maintain an account at a [Federal Reserve Bank](https://www.investopedia.com/terms/f/federalreservebank.asp) receive routing numbers. RTNs are associated with the American Bankers Association (ABA).

It's important to know how to find yours and to understand its applications in practical financial activities like wire transfers and direct deposits.

### Key Takeaways

*   A routing transit number (RTN) is a nine-digit code identifying U.S. banks for electronic funds transfers and check processing.
*   The American Bankers Association (ABA) established routing transit numbers in 1910, also known as "ABA numbers."
*   Routing numbers are essential for wire transfers, direct deposits, and domestic U.S. money transactions, but not for international ones.
*   Your bank's routing number is typically found at the bottom of a check or within your online banking portal.
*   A correct routing number ensures transactions are processed smoothly and securely.

## Understanding the Function of Routing Transit Numbers

A routing number is the first nine digits on the bottom left of a check. The first four digits designate the Federal Reserve Bank of the district where the institution is located. The next four digits denote the bank itself, while the last digit is a classifier for the check or [negotiable instrument](https://www.investopedia.com/terms/n/negotiable-instrument.asp).

Following the routing number on a check are the account and check numbers, indicating the bank. All checks written on state or federally chartered banks will have routing transit numbers on the bottom.

Paper checks have a routing symbol at the top that works like the bottom routing numbers. The routing symbol is located at the top of the check and is also called the [fractional bank number](https://www.investopedia.com/terms/c/check-routing-symbol.asp).

## Practical Applications of Routing Transit Numbers

Routing transit numbers are often used when setting up a [wire transfer](https://www.investopedia.com/terms/w/wiretransfer.asp) relationship with one’s personal or business bank. A wire transfer is an electronic funds payment across a network administered by hundreds of banks worldwide.

> **Important**
>
> Routing numbers are nine digits long, while bank account numbers often vary in length. In addition, your routing number will always begin with a 0, 1, 2, or 3.

While no physical currency moves among financial institutions during a wire transfer, information does pass between banks, including the recipient's account information, the receiver's bank account number, and the transfer amount. As a result, a correct routing transit number is critical to ensure sensitive information is directed to the appropriate receiving party and that the transaction goes through smoothly.

Employers use routing numbers for [direct deposits](https://www.investopedia.com/terms/d/directdeposit.asp#:~:text=Direct%20deposit%20is%20the%20deposit,called%20the%20automated%20clearing%20house.), like paycheck deposits and IRS tax refunds. A direct deposit allows a sender to deposit funds directly into the receiver’s bank account electronically instead of issuing a paper check.

## Comparing Routing Numbers to Other Banking Codes

A few terms are synonymous with "routing transit number," including "routing number," "transit number," and "ABA number." ABA is an acronym for the [American Bankers Association](https://www.investopedia.com/terms/a/aba.asp), which established these numbers in 1910.

The terms "routing," "transit," and "ABA" are often used interchangeably. Routing numbers were originally established for checking accounts but have since evolved to include identifying banks during electronic transactions as well.

### What's a SWIFT Code?

A [SWIFT](https://www.investopedia.com/articles/personal-finance/050515/how-swift-system-works.asp) code is a similar identification code used for facilitating banking transactions, although SWIFT codes are mainly used for international transfers.

Alternatively, an [international bank account number](https://www.investopedia.com/terms/i/iban.asp) (IBAN) is a lengthy alphanumeric code that identifies the country, check number, bank code, bank branch code, and bank account number of a transaction. It is also mainly used for international transactions.

## Important Considerations for Routing Transit Numbers

Before widespread internet and computer use, check fraud was a major problem. Fraudsters could falsify a routing number on a check and attempt to cash the check at a local bank. Without the banks being on an interconnected computer system, it was difficult to verify checking account routing numbers, leading to instances of fraud and theft.

LexisNexis Risk Solutions is the official registrar of routing numbers, and newly organized financial institutions must apply for a routing number. One financial institution might have different routing numbers for various payment methods. For example, a bank may have a routing number specific for [ACH transfers](https://www.investopedia.com/ach-transfers-what-are-they-and-how-do-they-work-4590120), paper transactions, or wire transfers.

## What Is a Routing Number?

A routing number is a nine-digit number used to identify a financial institution. Banks use routing numbers to process transactions, as the routing number tells all parties involved which institutions are involved and which parties are receiving or distributing funds.

## Where Can I Find My Bank's Routing Number?

Your bank's routing number can be found on the bottom of a paper check. Alternatively, you can often find the routing number when you log into an online banking portal. The routing number is usually in the same location as your account number.

## Which Numbers on a Check Are Routing Numbers?

When looking at a check, the furthest-left numbers at the bottom are your bank's routing number. The left-most nine digits are the routing number, while the right-most numbers are your account number and check number. The check number at the bottom of a check will correspond to the check number in the upper right corner.

## How Are Routing Numbers Used?

Financial institutions use routing numbers to communicate between banks. The number identifies the institution you use so that the transacting parties know where your account is located.

## The Bottom Line

A routing transit number, sometimes called an RTN, is a nine-digit number used to identify a bank or financial institution when clearing funds or processing checks. The American Bankers Association (ABA) established routing numbers in 1910. Routing numbers are also sometimes referred to as "ABA numbers." These numbers are often used when setting up a wire transfer or direct deposit and in online banking.

It's important to know how to find yours: at the bottom of a paper check—the first nine digits on the far left. The first four digits designate the Federal Reserve Bank where the institution is located. The next four digits denote the bank itself, and the last digit is a classifier for the check. In online banking, you can often find the routing number when you log in to a banking portal. It likely is reported in the same location as your account number.

> **Article Sources**
>
> 1.  American Bankers Association. "[Routing Number Policy & Procedures](https://www.aba.com/news-research/analysis-guides/routing-number-policy-procedures)."
>     
> 2.  Citizens Bank. "[What Is Direct Deposit? How It Works and Other FAQs](https://www.citizensbank.com/learning/what-is-direct-deposit.aspx)."
>     
> 3.  U.S. Treasury Department. "[Routing Transit Number (RTN)](https://tfx.treasury.gov/taxonomy/term/10773#:~:text=A%20Routing%20Transit%20Number%20is,electronic%20transfers%20or%20processing%20checks.)."
>     
> 4.  American Bankers Association. "[ABA Routing Number](https://www.aba.com/about-us/routing-number)."