British Airways has updated the award booking engine on britishairways.com to use the same engine that has been use on IAG’s Avios website. You no longer have to choose the engine to show partner airlines. They are now shown by default.
You just have to bear in mind that BA charges awards by every single segment separately (some exceptions apply within Europe) and just combines the segment prices to come up with a total.
Here’s an example of the new booking engine for HEL-BKK one-way in Y
Helsinki to Bangkok on a direct Finnair flight
The price is rather reasonable 25K miles but around $160 of the $180 “taxes” are fuel surcharges
Helsinki to Bangkok on a British Airways flight via London
The one-way is priced at 37500 miles and the “taxes” are $269.16.
Helsinki to Bangkok via London on Finnair/British Airways
The miles required is the same as on the BA only flights but the “taxes” are $289.
Helsinki to Bangkok via Narita on Finnair/JAL
BA wants 60K Avios and $347.35 for this combo.
The new award booking engine is better because it shows the partner airline inventory by default. You just have to make sure and check number of different options to find out the lowest price in Avios. As BA charges per segment, it is better to book a direct flight as a result. People who are not living in Oneworld hub cities are basically screwed.