Virtually every time I’ve flown in economy I’ve got to the gate and they’ve been asking people to check their carry ons there.

Rather than having to carry my bag through security and then the airport for an hour or 2 just to then hand it over anyway can I voluntarily check it in? It’ll be a standard carry on size and no bigger.

I know sometimes they text about doing it but I haven’t received one this time, but they seem to ask at the gate sometimes even without that text message.

This would be at Gatwick if that works differently to Heathrow. If it is possible do I have to go to a manned counter or can I use the self service to do it?