I bet the acquirer ends up taking the largest cut here, and it's the nearly perfect crime. The bulk of customers won't realize they've been cheated, and the few in the know can usually get out of DCC. Then you have cases where staff haven't been trained, POS terminals are locked, or things are setup in a way where a customer is forced into DCC. In this case the customer disputes the transaction, and the risk is on the merchant if a Reason Code 76 chargeback results. Now, this might have the effect of the merchant having a little chat with the acquirer and training staff, but that is after the fact.

I'd suspect in a lot of these cases the acquirers steer the payment terminals toward DCC such that disabling it is extremely unintuitive or the non-preferred option. It's just like the ANZ terminal in Brisbane at the coffee shop. The cashier was saying, "Oh. Press OK." The terminal was saying, "Accept exchange 1.03566 AUD?" or something similarly esoteric. If I hadn't had the terminal in my possession we would have had a problem because the cashier would have repeatedly pressed OK. I had to pause for 10 seconds to make sure I pressed the correct button (cancel) because that move was critical to generating the DCC free slip.