Originally Posted by chalf
LGW actually requires that one has a receipt before they will do the security check at check-in. Last week a free security checker waved me forward (past the line for receipts), only to tell me to go back to get my receipt (by which time the line had cleared).
Not only in London and Paris, they require the itinerary pre-checkin in Brussels and Buenos Aires too (though in BsAs they already had them printed out).