BT IS lobbying the media regulator Ofcom to scrap 0845 and 0870 numbers over claims that the supposedly low-rate prefixes are being used to rip off consumers.
Ian Livingston, the telecoms giant's retail chief executive, says the prices charged by rival operators for dialling the numbers can be six times more than the regulated prices charged by BT.
The 0870 national rate and 0845 local rate numbers are also used by a number of banks and credit card suppliers, including HBOS, Abbey, HSBC and Barclaycard.
The companies argue that the system allows them to advertise a single number without relying on local STD codes and does away with engaged lines, making it easier for customers, but Livingston says it also allows companies to skim a profit from customer helplines.
Although scrapping the numbers would cost BT money, ditching the numbers is now one of its top priorities in discussions with the regulator - alongside the need to clamp down on the mis-selling of telephone services.
Livingston said: "You have different providers offering wildly different prices for these numbers and the consumer no longer has any idea what the charges are or where that money goes.
"Ideally these numbers should just be swept away. Or if that can't be done, the regulator should insist that all operators charge exactly the same price for these numbers, as they do for a local or national call.
"I don't think the customer appreciates having to pay to use these numbers. I know people tend to look for the geographic number they can call instead of an 0870 or 0845 number because then they know what they are paying.
"This isn't a great idea from a BT revenue point of view, but if you make life simpler for customers it's better."
He said that for 0870 numbers BT charges 1.5p per minute at weekends, Homecall charges 5.8p, Onetel 1.5p, Telewest 2p and Ntl 2.75p
He is also complaining to Ofcom about the charge structure for making fixed line to mobile calls, where BT has to pass 80%-plus of the call charge on to a mobile company.
He said: "The way BT is regulated means we can't include these numbers in any call bundles we offer, which irritates and confuses people.
"Ofcom's worry is that there's a whole load of people who rely on the termination revenue - used for dial-up internet where a chunk of money goes back to the internet service provider [ISP] or your local bank. But we can't have the charges people levy for these calls."
BT is also lobbying Ofcom about mis-selling in the industry. Livingston said that if a customer is contacted by a salesperson from another telecoms company, they will often wrongly assume it is someone from BT.
Many complaints are about door-to-door sales - a practice BT does not engage in.
He said: "Last month we had 22,000 people calling us up saying they had been mis-sold to."