In summary, the ABA routing number is the unsung hero of the U.S. payment system—a small string of digits that ensures your money reaches the right destination safely and efficiently. Always double-check the number before initiating a large transfer, as using an incorrect routing number can lead to delayed or failed transactions.

In the world of U.S. banking, the ABA Routing Number (often called a routing transit number or RTN) is a critical piece of financial infrastructure. Standing for the American Bankers Association , which created the system in 1910, this unique 9-digit code acts as a bank’s digital “address.”

An ABA routing number identifies the specific financial institution responsible for a transaction. Unlike your personal account number, which points to you, the routing number tells the banking network exactly which bank holds your account. Every federally and state-chartered bank, credit union, and savings institution in the United States has at least one.