Originally Posted by Majuki

I'm glad this thread helped you on your trip. In the case of the second vendor, were you able to pay in GBP? If not, did you write "local option not offered" on the receipt before signing?

In the case of the first merchant, many of them feed you this garbage. There would be no additional fees on your card issuer's side if your card levied a currency exchange fee. However, most (all?) cards issued in the US have a foreign transaction fee rather than a currency exchange fee. This means that even if the transaction is denominated in USD, you will still get hit with a FTF if you card has one just because the purchase occurred outside of the US. Fortunately many good cards now have 0% FTF.

The rate for DCC usually a markup of 2-5%, and there have been few cases where the DCC rate has been cheaper than the bank's rate. Furthermore, going back to my previous point, if you're carrying a card with a 3% FTF, you're going to be paying anywhere from 5-8% when you add in the DCC and FTF.