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

https://wiki-saloon.win/index.php/Best_Way_to_Explain_Airport_Drop_Off_Fees_to_Someone_Giving_You_a_Lift

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