Have never come across this before. Not sure if it's an error with the way the fare is being advertised or how taxes are applied. Looking at BTR-LAX. Next week for example (7.3.18). UA6049 BTR-IAH to UA 832 IAH-LAX. "A" fare showing as $861 in the search. Select and go to buy, and then shows as $947.70 ($860.35+$87.35). The following week this happens again (only on A fares, as far as I can see - not P or Z).

Any thoughts would be much appreciated.

Thanks,