For many travellers, paying up to '5000 for a business class ticket in order to fly in greater comfort simply isn't an option. However, what very few people realise is that most airlines will upgrade passengers from economy class for free - if they meet certain guidelines. In this article, I will pass on some of the things that the check in staff look for and require so that you can take advantage of the loopholes and get your upgrade for free. These five top tips come direct from the check in staff of some of the best-known airlines, and are considered by many regular travellers to be the holy grail of getting something for nothing.

Tip Number 1:

Look the part. Make sure that you are dressed smartly when you travel. There is almost no chance of getting a free upgrade if you are wearing shorts and a scruffy t-shirt, so at the very least, check in wearing a shirt and pants. there is no need to go overboard and wear a suit - unless you really want to. The key is to look smart, but not like you're trying too hard.

Tip Number 2:

Turn up early. The check-in staff know exactly how many passengers are travelling on a particular flight well in advance, so if there are seats to spare in business class, they will know straight away.

Tip Number 3:

Be Polite. Put yourself in the place of the check in staff. Would you reward a person who gives you attitude and starts shouting the odds, or someone who is pleasant and gives them the time of day. There may be 250 people in the queue behind you, so make them remember you. Flirt, smile, use their name, be nice, and you may well get a pleasant surprise.

Tip Number 4:

Be a Frequent Flier. If you join an airline's frequent flier programme, you are far more likely to be at the front of the queue for an upgrade, as the airline will want to reward you for your loyalty. Even if you do not fly regularly, go to the airline's website and join their programme online. It will only take a minute or two, and is well worth the time.

Tip Number 5:

Ask. They say that if you don't ask for something, you won't get it, so make sure you do - but do it at the right time. If the check in staff look stressed, and no amount of charm has elicited a smile, don't bother to ask them, wait until you get to the gate. If the counter staff have responded well, when they ask you if you have any specific seat request, be cheeky and say "First Class" to them. It might just work.