Is there a place in Gatwick we can securely leave car keys for someone to collect a few hours later?

[Solola]

Doing a house and car swop with a french family. We will take our car to Gatwick and park it and then they will arrive a few hours later and drive it back to our place. Does anyone know if there is a place in Gatwick where we could leave our house keys, car keys and parking ticket for them to collect when they arrive?

Could you post them a set of keys? And then leave the parking ticket in the glove box?

We had to do something similar at East Mids airport last year. We arranged with the airline that they would keep it at their ticket sales desk and would be collected by password. They put them in their safe for us. Believe it or not but it was Ryanair that did this.

We have done this twice before. We've left the car keys on the top of the tyre under the wheel arch (previously specified and texted them the location of the car), the car park ticket in the glove box and the house keys in a hidden location at our house.