Originally Posted by
Airprox
No they must use the daily published IATA Consolidated Exchange Rate, which is specifically designed to make sure all IATA airlines are using the same reasonable rate. It is indeed fairly accurate and not designed to profit the airlines unlike your credit card forex rate.
Yes, agreed it's the IATA ICER rate which is derived 70% from the Forex company Oanda and 30% from bank rates. In reality, given I don't think there's any way to get the ICER figure without paying, if you use pretty much any reputable currency conversion website for approximate verification there won't be a lot in it.
You certainly don't want to be disputing a 20p difference!