Ofcom is about to call time on mobile networks and businesses charging consumers high rates to call 0800 numbers from mobile phones that would be free from a landline.

According to research carried out by the regulator, tariffs to call apparently ‘freephone’ lines can cost consumers up to 40 pence per minute from a mobil. Adding calls to non-geographic numbers, this generates £1.9 billion a year in easy profits for networks and large companies.

The proposal is part of a suggested streamlining of the structure of phone numbers in the UK to make call costs clearer to consumers. As well as making 0800 numbers universally free, premium rate numbers would begin with ranges 090, 091 and 098, lower, and fixed-rate calls with 0843/4/5, and 0871/2/3.

This approximates to the current situation, but the difference is that the changes would be mandatory rather than, as now, optional. It is the optional nature of the current number and charge combinations that causes confusion.

Ofcom also wants the cost for calling fixed-rate and premium-rate umbers to be clearly broken down so that callers can see how much is being charged by a company running the line, and how much is being charged by the service provider.

‘Consumers need to have far more transparency about the price they are going to pay for calls so that they can make more informed choices and so competition can work more effectively,” said Ofcom Chief Executive Ed Richards.

The idea is still at the consultation stage with the consultation document online here.

Although genuinely free calls to 0800 numbers is good news for mobile users, the bigger story could be the way the proposals could make clearer how much the UK’s big service companies are making by adding a premium on top of call rates to bolster profits.

According to Ofcom, calls to such lines (for instance 0845 numbers) costs consumers around £900 million a year.