Dropping someone off at a UK airport can cost you more than you might...

https://wiki-site.win/index.php/How_Do_I_Budget_Airport_Access_Costs_for_a_Return_Trip,_Not_Just_Drop-Off%3F

Dropping someone off at a UK airport can cost you more than you might think—take Gatwick, where it’s around £10 just to stop briefly. Heathrow’s about £7, with average fees across airports around £6.51