A bank routing number on a check is an essential identifier used to facilitate electronic funds transfers. It is a unique nine-digit code printed on the lower left corner of checks, after the account number. For instance, in the check number 123456789, the routing number is the series of numbers 011000025.
Bank routing numbers are crucial for processing financial transactions, ensuring funds are securely transferred between banks. Before the advent of electronic banking, paper checks were the primary method of payment. However, processing paper checks was time-consuming and prone to errors. The introduction of electronic funds transfer systems in the 1970s revolutionized the banking industry, and routing numbers became indispensable for automating the clearing and settlement of electronic payments.