Originally Posted by
clubman
Isn't that the same...?
If you cancel then you enable BA to release the seat back into the availability pool for another pax to buy or maybe to redeem miles against.
If you don't cancel then you no-show and the seat may be empty when the flight departs.
I guess this may make little practical difference to the OP at T-24 or later but it may make a big difference to another pax who is waitlisted for a seat on an over-sold flight.