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I’ve seen various questions on TSE about ruses to ‘’sneak’ into a higher grade cabin than the one paid for. I’m interested to know what the chances are of being upgraded legitimately (i.e. by the airline) on a long haul flight and what, if anything, a relatively infrequent non-business traveller can do to improve their chance. In all my years of flying on vacations, I’ve only ever been upgraded once with BA, and that happened simply by asking politely at checkin.