Canadian Business Credit Card Credit Card Charges & Exchange Rates: Uses Trans Date Or Post Date?

Credit Card Charges & Exchange Rates: Uses trans date or post date? - canadian business credit card

If buying a U.S. map Flights from sites in Canada (airfare is usually at a later date much later), is a credit card, the exchange rate at the date of the requested transaction or when you really? The reason I ask is that I make the comparison of costs for business and personal travel.