Aba-Transit-Number (ATN): A nine-digit code used by banks in the United States to identify financial institutions for electronic money transactions. This unique number is typically written on the bottom of a check and can be used when setting up direct deposits or automated payments. By utilizing an ATN, you’ll save time and effort that would otherwise be spent finding bank routing numbers and identifying payment recipients. Investing wisely means making your life easier – so don’t forget your ATN!