Originally Posted by Captain Schmidt

I've always assumed this to be the case, however I was recently in Portugal and I realised after the fact that one of my charges had used DCC and the payment processed in CHF. Interestingly I got a better exchange rate on the DCC payment than the other transactions that were transacted in Euro that were incurred the same day (and posted to my Mastercard account in CH the same day). I keep meaning to try this again to do another comparison.