Just back from Marrakech and one restaurant charged in in USD and did the conversion scam. I told them I wanted to pay in local, but the receipt came back converted. I told the waiter. Manager. Owner. All refused to switch the transaction. The owner insisted that he always charges customers in their home currency and that everyone wins, he is doing us all a favor by making things easier. I told each of them they were full of it. The "discussion" escalated, my wife told (tipsy) me to stop being foolish by arguing with them and just leave (smart advice), which we did.

I'll dispute the transaction (this isn't abut a few dollars on a $200 tab, it is principle and fraud -- and apparently a very popular restaurant that does this as a matter of course. No clue what Visa or Chase Sapphire Reserve will do (experience welcomed).

Question: I noticed on this last trip that being able to tap meant over 90% of businesses never asked me for a signature even though I have an American card that is not chip+PIN. In this case he tapped my card out of my vision and handed me a receipt. I never signed anything. Is this officially allowed now for certain transactions or did vendors just do it out of convenience and pattern of dealing with non-American cards? Does my lack of signature help my dispute claim?

As an aside, man, the ATMs in Portugal were quite confusing. We fell for the scam on our first need for quick cash but then (thanks to FT!) started rejecting the conversions, but the phrasing makes it sound like you are cancelling the entire withdrawal vs just the DCC (even at the post office ATMs)... never seen anything like it.