How does easyJet justify an £8 booking charge for paying with a debit card for a £32.99 flight from Luton to Edinburgh? For an online service, 24 per cent is despicable. Will the Office of Fair Trading ever look into this "captive" type of charge? Holly Smallman, West London

The UK's leading low-cost airline insists it is doing travellers a favour with its "flat rate" booking fee of £8, claiming it "remains one of the cheapest across the airline industry". It is certainly the case that Ryanair charges £6 per person per flight, while Bmibaby's flat fee of £4 applies only to a single flight then rises to £3 per person per flight. But for one traveller who just wants one flight, the £8 fee is onerous – and ridiculous, given that the transaction cost to easyJet is less than 20p.

The airline insists, opaquely, that "the booking fee covers a range of activities and easyJet has experienced significant cost increases in a number of those areas". It also points out: "In addition, easyJet offers the free option to use Visa Electron". Yet far fewer people have these cards, which are mainly aimed at people in challenging financial circumstances.

What easyJet is doing, in common with some other low-cost airlines, is seeking to make its basic fares look artificially low by charging a disproportionate "booking fee". Travel is the only industry in which surcharges are so high.

In June, the Office of Fair Trading said that "to make headline prices truly meaningful and comparable" there should be no charge for paying with any debit card. This month the OFT has launched a formal investigation into airlines that are still levying debit-card charges.

Meanwhile, all you can do to avoid the swingeing charges is to obtain a Visa Electron card, such as that issued by Virgin Money.

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