and some may even have routing numbers unique to specific transaction types. What Is the Nine-Digit ABA Routing Code? The American Bankers Association routing number, or ABA routing number ...

If you have paper checks, your routing number is the nine-digit number on the bottom left. It's followed by your account number in the middle and the specific check number on the right.

CUSIP numbers uniquely identify North American ... and whether you really need to learn a nine-digit alphanumeric code to buy stocks. Image source: Getty Images. The codes were created in 1964 ...