Here's a good example of so-called dynamic currency exchange. When I checked out of the Sheraton on the Park in Sydney I was presented with a bill for incidentals stated in Australian dollars, but the credit card slip came in US dollars for $244.11. It had written on it in huge bold-faced letters 'no commission'. I refused to sign the charge in US dollars and requested the charge in the original amount in Australian dollars. The charge showed up on my CapitalOne VISA converted to $233.13, a difference of $10.98, or 4.7%. It is true, of course, that on a typical US credit card with a forex fee of 3% the charge might have been as high as around $240, but this so-called no commission currency conversion is even more expensive. The lesson seems to be that conversion to US dollars abroad should also be refused.