Airlines have declined to comment on reports that high hidden charges in the small print of airline fares could be outlawed.
The Law Commission, which reviews and recommends reform of the law, says courts should be given a new power to ensure any hidden charges are fair.
The popularity of price comparison sites has tempted firms to highlight low headline prices, with many then hiding extra costs in the small print, its report said.
Under the reforms, which could also affect mobile phone contracts, cancellation charges for weddings, payday loans and estate agents, courts would be able to intervene to stop any unfair hidden charges, the Daily Telegraph reported.
Judges would have to distinguish between the clearly displayed terms which consumers would have been aware of when buying a product or service, and those which may have been lost in the small print.
David Hertzell, the Law Commissioner leading on the project for England and Wales, said the reforms “target businesses that hide all the extras, which are almost certainly what you’re going to need to have to get what you thought you were paying for”.
He reportedly said: “If you want to rely on something in your contract, such as the price, then you’ve got to tell the person about it.
“You can’t give them 200 pages of small print and expect them to work it out for themselves. You’ve got to put it right upfront and say, ‘this is what you’re going to pay, and this is what we’re going to give you’. You’ve got to tell them in plain English.”
He added: “If a price is transparent and prominent, the courts should not interfere – but other charges need to be fair.
“Our approach gives traders control over what charges are exempt from review – provided they put them upfront.”
The joint report by the Law Commission in England and Wales and the Scottish Law Commission said: “In a world of price comparison websites, there is increasing pressure on traders to advertise low headline prices, whilst earning their profits through other charges.”
The Department for Business, Innovation and Skills, which asked for the review, welcomed the advice, saying its findings “provide a good evidence base for Government as we develop plans for a new Consumer Bill of Rights”.
“We will be considering their contribution as we develop the Bill and will respond formally as part of that process,” a spokesman added.
Several carriers, including Ryanair and easyJet, refused to comment.