Not sure anyone remembers but way back in the past BA site has wrongly calculated the taxes charged on the Avios booking in that it has added certain taxes that are exempt from award booking to its calculation.

I was checking a YYZ-MIA Avios booking - I had same ticket in Feb when the taxes charged were $50.90 when AA site shows $51.4. The difference most likely due to different exchange rate is being used when converting the CAD to USD.

Today I checked the same routing again, BA shows a $69 cash payment, but AA only asks for $55.10.

Initially it looks like it is doing it again, but luckily only on the first screen. When it goes to the actual booking, it shows the correct taxes.

I decided to see what make up the $69 by going further to the booking process, the figure shown on the next screen changed to $51.40 - that is lower than AA charges by a few bucks.

Since AA does not show any breakdown of the taxes, so there is no way to know where the discrepancies coming from.

Has anyone noticed such oddity the way BA shows taxes?