Can we advertise our ATM as FREE if we do not charge a fee on any AMT's in our network but if they use it at a non-network one that ATM owner may charge them a fee?

In the private forums, someone posted a question regarding whether you can advertise free debit cards. I think the same reasoning would apply here.

John Burnett responded: "in today's UDAP/UDAAP environment, I'd always suggest that you include a disclaimer that 'If you use an ATM not owned by XYZ Bank, you may be charged a fee by the ATM operator or network.'"