UK mobile phone buyers are not being given sufficient information about how to cancel contracts if they encounter coverage problems, a study has found.
In secret shopper tests, the Communications Consumer Panel found that over half of shoppers were given inaccurate information.
It also found that some firms allow cancellations due to coverage issues while others do not.
The panel called on mobile firms to offer consistent guidelines.
Panel chair Anna Bradley said that consumers must be given simple and accurate information before locking themselves into contracts that they might not be able to leave for up to two years.
"We are calling for an across-the-board minimum 14 days to cancel contracts where consumers have coverage problems," she said.
The time limit allowed by mobile firms for cancelling contracts currently varies dramatically, the study found.
Most, with the exception of Orange, allowed customers some period of grace.
Virgin Mobile gives customers 28 days to cancel, compared to 14 days for 02 and Tesco Mobile, and 7 days for Vodafone and T-Mobile.
3 came out best in the survey. It has no time limit on cancellations due to coverage issues and only 4% of shoppers were given inaccurate information.
"Whilst we are significantly expanding our network, we accept the fact that no mobile operator can have total blanket coverage, which is why we have this policy in place," said a 3 spokesman.
Orange, on the other hand, does not allow users to cancel contracts because of poor coverage.
"When a customer purchases a handset and then returns it to us, the handset becomes second hand. As such we are not able to offer a formal money back guarantee.
However we are aware that sometimes issues do arise, which is why a reasonable and flexible approach is applied. If a customer is deeply unhappy with their purchase from a store we will will always consider their issue on a case by case basis," said a spokesperson for Orange.
The study found that stores themselves seemed unsure of the policies of individual mobile firms.
Carphone Warehouse wrongly told people that T-Mobile had no cancellation policy for coverage issues, while Phones 4U said that Orange did allow cancellations when it does not.