Routing number: Along the bottom of your checks are three sets of numbers. The first nine digits, between symbols resembling colons, are the routing numbers. They identify the financial institution associated with an account and are often prominently displayed on the institution's web page. You need these numbers to set up direct deposits or automatic payments. Account number: To the right of the routing numbers is the account number, which is unique for each account holder. Check number: The last set of numbers reflects the check number, which you'll also find on the top right-hand corner of a check.