ATMs allow you to make deposits or withdraw cash 24 hours a day, seven days a week. Despite their convenience, however, ATMs cost the banks money to maintain, and those costs are passed on to you. The ATM fees you pay are usually a combination of charges for the services between the ATM and your bank account. If you're using your bank's ATM with a direct link to your account, the transaction may be inexpensive or free. But if you use another bank's ATM, you'll probably pay a fee to access your account over a commercial ATM network, such as Visa/Plus. ATM networks charge banks for their services, and the banks on both ends of the chain can charge you to cover their costs.
The sneakiest part of ATM fees is how they can add up for a single transaction. For example, if you're out of town and use a large commercial bank ATM that's on the Visa/Plus network, you agree to pay a $3 ATM fee in addition to your $60 cash withdrawal. Later, your bank charges an additional $3 ATM fee for completing its end of the transaction. That means your one transaction cost you a total of $6, which is 10 percent of your original withdrawal.
For more information on banking and fees, keep reading.