National Bank is significantly smaller than the big five banks in Canada but does offer foreign currency exchange services. How do National Bank exchange rates compare? Not very well.
A recent survey looked at National Bank exchange rates relative to the best available rate from a reputable foreign exchange dealer and here is what it found. Almost in all circumstances, the National Bank exchange rate was worse. Below is a table of some of the currencies from the survey and the savings from using Interchange Financial instead of National Bank.