Originally Posted by
zebranz
Before I call usually duplicate on ITA and get Fare Basis to give to agent (if needed) to see if available on the flight(s).
This is the best thing to do. If ITA will give the price, using the correct POS, then a call to BA will almost certainly get you the fare.
Remember to deduct £10.50 each way (technically, per fare component) from the ITA fare quote to allow for the GDS fee that ITA quotes include but BA does not charge if you book directly, even if BA charges the offline fee (which it does not always do).