The amount you’d spent appeared on your bill. Maybe you paid a small conversion fee, but you also got a competitive exchange rate.

The dangers of dynamic currency conversion

Processing a credit card charge for overseas purchases used to be pretty simple. You swiped your card while on vacation, your bank changed the money from pesos or euros into greenbacks, and the amount you’d spent appeared on your bill. Maybe you paid a small conversion fee, but you also got a competitive exchange rate.

They wanted to pay their bill in dollars, because they'd avoid Bank of America's three percent foreign transaction fee.

Exchange rate rip-offs, and how to avoid them

As Jay Berman and his wife were checking out of the Henley House in London last month, a clerk asked if they wanted to pay their bill in dollars. It seemed like a good idea at the time, because they’d avoid Bank of America’s three percent foreign transaction fee.