Originally Posted by MDtR-Chicago

There was a lawsuit a few years ago - https://www.ccfsettlement.com/home/ - about how the fees for foreign transactions were hidden by the card networks. To my recollection, that hidden 1% Mastercard fee was required to be clearly published as part of the card's FTF now...

What you should be seeing now is a transaction post in USD based on the published exchange rate used my Mastercard on the settlement (posting) date of the transaction, not the actual purchase date.

So if I bought something for GBP 10 on 1-June-2014 that posted to my account on 3-June-2014, using https://www.mastercard.com/global/cu...ion/index.html I should see: 10/0.595912 = USD $16.78 on my statement.

If you're seeing a difference between the Barclay card and a Visa card, it should be because of a combination of Visa using a different published exchange rate and/or the transaction posting on a different date.

This all supposes you take the transaction in the LOCAL currency. If you instead ask the merchant to process in USD directly, you are subject to a Dynamic Currency Conversion (DCC) fee charged by the merchant's bank, which can easily be 3%+ on top of any other fees. We have an entire thread on DCC: http://www.flyertalk.com/forum/credi...er-thread.html

If you're seeing something different from what the Mastercard conversion tool predicts, it would be interesting to see if there is a pattern. Maybe Barclays is bending the rules. (Or they are still passing along that hidden 1%)