History

• According to Cambridge University, checks date back to at least the 12th century. However, it wasn't until the 1500s that checks became widespread. British banker Lawrence Childs issued the first printed check in 1762. As the number of bank accounts and checks grew, a system to keep track of checking accounts and banks became necessary. In the 1700s, bankers devised a clearinghouse system with standardized checking account numbers; a system of routing numbers associated checks with particular banks. In much the same way, modern checking account numbers identify a particular account holder and banking institution.
  
  

Purpose

• Checking account numbers associate checks with their originating banks and accounts. They also allow account holders to make direct deposits, and to access their accounts through Internet banking, telephone banking and automated teller machines (ATMs).
  
  

ABA Routing Number

• Every bank account number has a nine-digit American Bankers Association (ABA) routing number, or routing transit number, that is unique to a particular banking institution or clearinghouse. This number routes checks to their issuing banks.
  
  

Assignment of Numbers

• Since 1911, Accuity has been the official registrar of routing numbers for the American Bankers Association. It is responsible for assigning routing numbers to banks, and banks are responsible for assigning individual checking account numbers to their customers.
  
  

Location

• The checking account number appears on the bottom line of the check, and comprises numerals printed in machine-readable magnetic ink character recognition (MICR) code. The account number consists of three sections: the first section is the ABA routing number, the second is the account number and the third is the check number.