Originally Posted by
KeaneJohn
if you rent a seat in the interim yiu can see if BA will cover this cost but typically on homeward journeys you shouldn’t need to buy essential items as you should have this at home.
OP should have a back-up car seat at home?
Recently experienced the same scenario on AC at La Guardia. Very different outcome, they gave us a spare car seat (sourced from another airline as they had given all of their own away).