How to get a flight upgrade

If you've got close friends at the check-in desk, or better still, higher up in the airline, they may be able to wangle you occasional special privileges. Some airlines also give their staff upgrade vouchers, which'll effectively buy you an upgrade if there's a higher-class seat available.

Remember, an upgrade will put you into the posh cabins, so while an old T-shirt and flip-flops might be comfortable, an airline is less likely to put you in with its top-paying customers if you don't look the part.

If you're off on your honeymoon, jetting away to get married, celebrating a 70th birthday or on another special occasion, let the airline staff know.

If you know a member of the airline staff, tell them, otherwise do it via a travel agent or drop it in while at the check-in.

This trick is well-known and is regularly tried with check-in staff, so it can help to take a copy of your wedding documents.

It won't always result in an upgrade, but you may possibly get a free glass of champagne and some special in-flight treatment.

If you order a special in-flight meal in advance – such as vegetarian, vegan, halal or kosher – you may destroy your upgrade potential. Flights rarely carry spares, especially for higher-class seats whose food costs more.

If a flight's completely full, check-in staff will look for people to be "bumped off" onto the next one and offering incentives can make it worthwhile.

To tempt passengers to give up their seats, airlines offer upgrades for the next flight, or even cash, as compensation for those who volunteer themselves.

These offers are popular among travellers able to kill some time in the airport, and go fast, so it's worth thinking about it in advance and mentioning to check-in staff if you would consider being bumped.

One MoneySaver reported being offered flights to "anywhere in the world" as compensation for inconvenience.

If you're on the plane and the cabin crew ask you to move, there's a good chance you'll get rewarded for being nice.

If you're asked to move, or the cabin crew ask for a volunteer to move so a family can sit together, or for a particularly tall or large passenger, always agree to it.

Often this is how you'll be upgraded, but you won't necessarily know that's where you're going beforehand.

Conventional wisdom says your best chances of being upgraded are if the economy section's packed. But it is also true that quieter flights have more room for upgrades.

The most likely upgrade scenario is if the economy section is full and the class above it isn't, so flights in school holidays to popular holiday destinations are a good bet, though that's also one of the most expensive times to fly.

By the same token, early morning routes between city business hubs are hellish to get upgraded on as business class is likely to be packed already.

You've twice as much chance of finding a spare seat in a business cabin that has 40 seats than one that has 20, so it's worth investigating what's on offer in advance. The websites SeatGuru and SeatExpert catalogue the seating plans of all planes used by major airlines.

Different airlines use different planes, often with different seating layouts. This can have a big impact on how much legroom you get and makes a big difference when you're six hours into a 10-hour flight.

The critical measurement is 'seat pitch'. This is the distance between any part of one seat and the exact same part of the seat in front/behind. Check out SeatGuru's comparison charts to see which airlines offer the best seats.