Holidaymakers booking budget flights are advised to be extra wary of stealth booking charges, which are even higher than usual this summer.
These sneaky fees levied for everything from baggage to boarding cards force flight prices far higher than the advertised rate. So how you avoid these expensive extras?
We reported earlier this year how more airlines are adopting the budget airline pricing model of charging for luggage.
It is a profitable move and airlines earned $27.1bn (£17.3bn) in extra charges and fees last year, according to research by aviation consultancy IdeaWorksCompany. This is almost 20% higher than 2011 and this year's total is expected to be even higher as fees continue to rise.
When booking a flight and comparing deals, the key point to remember is that budget airlines are only able to offer cheap flights by clawing in revenue elsewhere. The service is basic and booking terms are stringent, with any optional 'extras' charged at a premium.
"Our love of cheap flights has been soured with airlines seemingly adding on more and more so called 'hidden charges' to our bookings," says Bob Atkinson, travel expert at Travelsupermarket.com. "That £49 flight to the sun soon escalates to well over the £100 mark."
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Using a mobile phone to make and receive calls, send texts and browse the web while abroad can be extremely costly – especially if you are travelling outside the European Union (EU), where calls can cost up to 10 times as much as at home.
To avoid high charges, Carphone Warehouse suggests tourists ensure a data cap is in place, use applications to check data usage, turn off 'data roaming', avoid data-intensive applications such as Google Maps and YouTube and use wi-fi spots to update social networking sites.
Payment Protection Insurance (PPI) is supposed to help people to continue meeting their loan, mortgage or credit card repayments if they fall ill or lose their jobs. However, policies are often over-priced, riddled with exclusions and sold to people who could not make a claim if they needed to.
At one point, sale of this cover - which was often included automatically in loan repayments - was estimated to boost the banks' profits by up to £5 billion a year.
Now, though, consumers who were mis-sold PPI can fight back by complaining to the bank or lender concerned and taking their case to the Financial Ombudsman Service (08000 234567) should the response prove unsatisfactory.
It could be you, but let's face it, it probably won't be. In fact, buying a ticket for the Lotto only gives you a 1 in 13.9 million chance of winning the jackpot.
With odds like that, you would almost certainly be better off hanging on to your cash and saving it in a high-interest account.
No-frills airlines such as EasyJet may promote rock-bottom prices on their websites. But the overall fare you pay can be surprisingly high once extras such as luggage and credit card payment fees have been added - a process known as drip pricing.
Taking one piece of hold baggage on a return EasyJet flight, for example, adds close to £20 to the cost of your flight, while paying by credit card increases the price by a further £10.
It may therefore be worth comparing the total cost with that of a flight with a standard airline such as British Airways.
Cash advances, which include cash withdrawals, are generally charged at a much higher rate of interest than standard purchases.
While the average credit card interest rate is around 17%, a typical cash withdrawal of £500, for example, is charged at more than 26%.
What's more, as the interest accrues from the date of the transaction, rather than the next payment date, costs will mount up even if you clear your balance in full with your next payment.
Supermarkets such as Tesco and Asda often run promotions under which you can, for example, get three products for the price of two.
However, it is only worth taking advantage of these deals if you will actually use the products. Otherwise, you are simply buying for the sake of it, which is a waste of your hard-earned cash.
Buy a train ticket at the station on the day of travel and the price is likely to give you a shock - especially if you are travelling a long distance at a busy time of day.
However, you can cut the cost of train travel by 50% or more by going online and making the purchase beforehand - especially if you book 12 weeks in advance, which is when the cheapest tickets are on sale.
Other ways to reduce the price you pay include avoiding peak times and taking advantage of so-called carnet tickets, which allow you to buy, for example, 12 journeys for the price of 10.
Most High Street banks offer packaged accounts that come with monthly fees ranging from £6.50 up to as much as £40, with a typical account charging about £15 per month.
Various benefits, such as travel insurance and mobile phone insurance, are offered in return for this fee. But whether or not it is worth paying for them depends on your individual circumstances.
Overseas money transfers or travel money purchases attract the same high rate of interest as credit card cash withdrawals.
Worse still, most credit cards – and debit cards – also charge you a foreign loading fee if you use them to make purchases while abroad.
You can, however, avoid these charges by using a Saga Platinum or Nationwide Building Society credit card.
Numbers starting 0871 cost 10p or more from a landline, while those starting 09 can cost more than £1 a minute from a mobile phone.
And the operators of these high-cost phone lines, some of which are banks, often get a cut of the call charges.
Most 09 numbers are linked to scams and should therefore be avoided at all costs, while 0871 numbers can often be bypassed by searching for an alternative local rate numbers on the saynoto0870.com.
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All low cost and charter airlines will charge you for putting a bag in the hold. It can be as much as £45 each way on Ryanair, costing a family of four £360 in bag fees alone.
"In addition some airlines charge you for checking your bag in, adding a check-in fee to the bag as well as the bag charge itself," warns Atkinson. "Watch out for this on bmibaby and Jet2."
Turning up with more baggage that you are allowed accrues the heftiest charges with excess baggage charges as much as £20 a kilo at the check-in desk. Avoid this by always weighing your bags at home and pre-booking your extra weight or bags online.
Hand-luggage terms are equally strict with size and weight allowances varying widely between airlines, so always check before you travel. Thomas Cook is the stingiest with just 5kg and only a small bag allowed in the cabin. If an airline finds your bag is too big at the gate, you can face paying up to £40 for it to go in the hold.
Costs for travelling with children have also increased this year. A Ryanair, parents can expect to pay £30 each way to take a child under two on your lap, up from £20 last summer. At Monarch, an infant ticket has increased from £15 to £20 each way.
Budget airlines often charge you to check-in - a bizarre and extremely annoying fee for what is a compulsory part of travel.
Pay close attention to Ryanair's online check-in requirements: Not only are you required to check in online, you must also remember to print your boarding pass and take it with you. If you forget you'll be charged £40 just to re-issue it.
Easyjet and Ryanair don't allocate seats but offer 'priority boarding' at a cost of £10 each way per person. The idea is that you'll get the the pick of the seats, but this often doesn't happen in practise as if you are bussed to the aircraft you could get stuck behind who haven't paid for the service.
While credit card booking charges have fallen thanks to new legislation introduced in April to prevent excessive surcharges, many airlines have simply sneaked them in elsewhere.
Travelsupermarket.com reports that that several providers have raised or introduced booking or administration fees that are unavoidable.
Aer Lingus has increased its each-way booking fee of £6 per person to £7, although it no longer charges for credit or debit cards. EasyJet introduced a £9 flat booking fee last year. This has now risen to £10, which is in addition to its 2.5% charge if you pay by credit card.
The flurry of extra charges often brings the price of so-called budget airline flights inline with regular airlines, so it is crucial to always shop around and never assume that budget offers the best price.
Look out for the overall price of a flight including fees and taxes, and take your time when booking online to ensure you pre-pay for what you need to avoid surprise charges at check-in.
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The British pound has strengthened against the Japanese Yen by 14.8% compared to 12 months ago.
The pound is stronger than the Argentinian Peso by 11.7% compared to 12 months ago.
The British pound has strengthened against the South African Rand by 11.5% compared to 12 months ago.
The pound is stronger than the Jamaican Dollar by 8.9% compared to 12 months ago.
The British pound has strengthened against the Egyptian Pound by 8.6% compared to 12 months ago.
The pound is stronger than the Gambian Dalasi by 8.1% compared to 12 months ago.
The pound is stronger than the Brazilian Real by 3.3% than it was 12 months ago.
The British pound has strengthened against the Mauritius Rupee by 2.3% compared to 12 months ago.
The pound is stronger than the Russian Ruble by 1.7% than it was 12 months ago.
The British pound has strengthened against the Indonesian Rupiah by 1.4% compared to 12 months ago.
If you are a victim of a strike, or any other event beyond the airline's control (including ash clouds!), they must offer you a refund (in which case it's up to you to find a way home) or an alternative flight. While you are waiting for the flight you have the right to food and refreshment and accommodation.
If you are on a package holiday, your tour operator is entirely responsible for looking after you until you get back to the UK.
This is more likely to happen due to the financial crisis, but in some situations you are covered.
If you pay by credit card and it's over £100, you'll get a refund from the card company.
Your travel insurance may well cover you too, but check before you go.
Talk to the airline, and if it is temporarily misplaced they should arrange for it to be sent to your accommodation, and you should be either given cash to cover the essentials in the interim.
If it's completely lost you must wait 21 days and then make a claim for compensation. If you are travelling as part of a package you can claim costs from your operator.
If you are travelling within the EU you need an EHIC card, which gives you access to public healthcare. However, this won't necessarily be free, and if you need extra services such as accommodation for a carer, a helicopter home or a delayed flight, you could end up seriously out of pocket.
The only protection that will guarantee you will be looked after without running up a horrendous debt is by having travel insurance - which often covers up to £10 million of costs.
The most common form of theft is pick-pocketing, followed by theft from a car and bag snatching. Meanwhile, 752,000 of those surveyed had items stolen from their hotel room or villa.
If you have anything stolen, your only protection is insurance. You need to tell the local police immediately and get a crime reference for your travel insurer.