Many mobile phone users are being given inaccurate advice when they ask for information about switching to another mobile network operator.
A survey published by telecoms regulator Oftel on Thursday showed that although mobile operators are giving better advice than two years ago, customers should be aware that there is still a significant risk of being misled.
Synovate, the research group that carried out the investigation, conducted 300 "mystery shopping" enquiries -- by visiting high street stores and calling or emailing customer support staff.
It found that 10 percent of inquiries about number portability -- where a customer keeps their existing mobile phone number when they move to another operator -- were answered incorrectly, with customers either told that this is impossible or that the person dealing with their query didn't know the answer.
Although 90 percent of inquiries were initially answered correctly, in many cases the support staff then went on to give inaccurate information about the cost of the transition, or how long the process would take.
Just one in three inquiries about number portability was answered correctly and in full, Synovate found.
Oftel's research also found that many mobile users are misled when they ask if they can keep their existing handset when changing operator.
Synovate found that just two-thirds of people are initially correctly told that it is possible to unlock their SIM card -- with 18 percent wrongly told it isn't possible, and 18 percent given a "don't know" reply.
And just 6 percent of people actually receive totally accurate information throughout an inquiry about SIM unlocking -- namely that they only have to pay a "standard charge" to keep their existing handset when they move networks, that the process would take less than 25 working days and that they could use their handset during the transition.
With so much misinformation being passed on, either deliberately or accidentally, by mobile operators, there is a big risk that customers may be deterred from transferring to another mobile network because they aren't given a true picture of the process.
Oftel, though, believes there is some cause for celebration. When this research was first conducted in 2001, the mobile industry fared even worse.
"The improvements in advice given on mobile number portability and SIM unlocking are encouraging," said Oftel in a statement.
"However, the results clearly show that the mobile industry has much to do in terms of raising the standard of advice it provides to consumers. Oftel would encourage the mobile industry to build upon the improvements made over the last couple of years, and will be watching developments closely," the regulator added.