Broadband adverts confuse public, says Citizens Advice
Broadband adverts have been criticised by Citizens Advice for misleading potential customers.
More than half of people would be unable to choose the cheapest deals when comparing the information in adverts, the charity said.
Three quarters of those in the research said information in the adverts was too complicated to make an easy comparison.
In particular, line rental costs were often not included in the advertised headline cost.
Earlier this year, Citizens Advice said that teaser deals in adverts were masking the long-term cost of broadband packages.
Gillian Guy, the chief executive of Citizens Advice, said the continuing problem with broadband adverts meant that potential customers were often left unable to make an informed decision.
"Attractive headline offers that don't include line rental costs make it impossible for people to work out the best broadband deal on offer without doing complicated sums," she said.
"Broadband providers need to make the costs of a contract clear in their advertising and the Advertising Standards Authority should also review the code of practice to make sure it works well for consumers."
In its latest research, Citizens Advice took a sample of just over 2,000 adults and split them into four groups.
Eight adverts, produced by seven unidentified companies, were selected by the charity and divided into four pairs.
Each of the four groups of people were then asked to compare a different pair of adverts, and also to look at marketing information on the websites of the companies involved.
The research found that 56% of those involved could not work out the cost of the deals on offer, and thus were unable to decide which was cheapest.
One advert, which the charity declined to identify, was so bad that only 22% of people in the research could work out accurately how much the deal on offer might cost them.
The charity said the source of the problem lay in the prominence given to temporary "teaser" rates, while at the same time the cost of line rental was often downplayed.
"The adverts typically are advertised with a promotional period featured prominently, which can be free or significantly lower than the overall cost of the contract," said Citizens Advice.
"The cost of line rental and the length of time that the 'teaser' price applies is included separately and often only in small print," it explained.
The Advertising Standards Authority (ASA) said: "We've conducted research jointly with Ofcom on this important matter and will be publishing the outcome of that work early in the New Year."