Telco watchdog Oftel has launched a campaign to stamp out misuse of 070 personal numbers, known as 'find me anywhere' or 'follow-me' numbers.
Numbers that start with the 070 code are valuable to people who travel and need to forward their calls on to another telephone number, including mobiles.
But calling these numbers costs more than a normal call and some of this revenue goes to the company or person that owns the number.
"Action is needed to stamp out the growing number of scams by people who use these numbers deceitfully as a way to make money," said Oftel's director general David Edmonds.
A common scam is to induce people to call the number, for the purpose of a lengthy call, and for the owner to then make money from them.
"There have been instances where people have been asked to fax back spurious lengthy surveys to a personal number at rates of up to 37.5 pence per minute," said Edmonds. "Oftel has written to trade associations asking them to warn their members to think twice before making lengthy calls to an 070 number."
Oftel is planning to ban or limit revenue sharing on 070 numbers in a bid to stop the scammers but to allow genuine callers to continue using the service.
The Independent Committee for the Supervision of Telephone Information Services Icstis is investigating the scams.
"We will not hesitate to impose sanctions against such services if they breach our code of practice," said Icstis director George Kidd.