Question

Why would a bank charge a fee to noncustomers who use it’s ATM?

ANSWER: Charging a noncustomer helps pay for the cost of keeping the ATM running and supplied with cash. Customers of the bank already cover the ATM costs with regular fees or by allowing the bank to loan out their money.

Answer 1

So what exactly is going on here?

Answer 2

Bank charges fee to non customers while using ATM. ATM's frequently charge fees to users who are not account holders from that same bank whose ATM you are operating.

This fee goes towards the compensation for the costs associated with owning and operating the machine.

Same bank persons pay many types of fee yearly to their banks, so same bank ATM do not charge any fee.

When using other banks, your bank has to pay some interchange amount to that bank, this is also the reason why banks charge fee, basically they recoup the money that they will have to pay to other banks for interchange.