I need to do a Mennens calculation for a part invol downgrade. The base fare is (relatively) easy as it’s a number of Avios, the taxes and surcharge less so.

These are the charges from my ticket (itin: LHR-SFO / LAX-LHR in F)

GBP PD 550.00YQ GBP PD 191.00 GB GBP PD 103.99XT GBP PD 48.89UB GBP PD 4.40AY GBP PD 16.60US GBP PD 16.60US GBP PD 3.00XA GBP PD 5.50 XY GBP PD 5.50 YC GBP PD 3.50 XF

Is the BA surcharge just the YQ?