Definition
A nine-digit code that identifies your bank or credit union for direct deposits, electronic transfers and checks.
What it means
A routing number, also called an ABA routing transit number, is a nine-digit code that tells the payment system which financial institution holds an account. You find it at the bottom left of a paper check, in your online banking app or on the bank's website. Employers need the routing number and your account number to set up direct deposit, and the IRS asks for both if you want your tax refund deposited. Some banks use different routing numbers for wires and for ACH transfers, so check which one a sender needs. A routing number is public and identifies the bank, not you, but your account number should be shared only with people and companies you trust. Typing one digit wrong can send a payment to the wrong place or cause it to be rejected.
Example
On a check, the first nine-digit number on the bottom line is usually the routing number (for example 0XXXXXXXX), followed by your account number and then the check number.
Illustrative numbers only. Your situation will differ.