If the rules were like that for commercial transactions like buying products for export from Brazil then trade would stop overnight.In theory BT`s view sounds right. The only problem I understand, is that, in reality, you cannot buy reais. When making payments for property as an individual you have to send the money in sterling or euros, it converts to dollars and then to reais. this is done when the money arrives not before it leaves. The rate may be fixed only when the money arrives in the receiving banks` hands, and only when the recipient signs his contract to liquidate the foreign currency into reais. Commercially the rules may be different, I do not know.