Simon Read: Here's a simple system to help you hang up on those costly 'free' calls

Do you ever use freephone numbers? They're a great way for companies to allow customers to contact them without having to pay a packet for the privilege. Except if you use a mobile phone – as most of us do – you'll have been charged a bundle every time you use a freephone number.

In other words, freephone numbers aren't free at all. Unless you call from a BT landline, that is. Confused? That's just the start of it. There is a bewildering array of what are known as non-geographic numbers, all seemingly designed to trick you into paying a hefty premium when you make a call.

But that's set to change. 0800 phone numbers are to be made free from all phones, while the telecoms watchdog plans to force firms to tell customers exactly how much they will be charged when they use 0845 and other non-geographic numbers.

Calls to numbers starting 08, 09 and 118 will be standardised with a single "access charge" plus a service charge set by the business that is being called. The numbers are used widely by companies such as banks, energy providers, entertainment services and directory enquiry firms.

The reason is simple: they are revenue-sharing lines. That means the company you call and phone operator make a decent profit every time you use one of the numbers. In other words, everyone's making money except the mug making the call.

Shockingly, even some doctors' surgeries and health centres are still making their patients call expensive 0844 numbers – which can cost 41p a minute – even though they were effectively banned from using them by Government guidelines published more than two years ago.

The Department of Health ruled in 2011 that patients should not have to pay more than a standard geographic charge to call their doctor. But it emerged this week that many GP surgeries are continuing to use the revenue-raising numbers, which leave patients racking up large bills when trying to get treatment or advice.

That's obviously one major problem with which the telecoms regulator, Ofcom, has got to get to grips.

In the meantime, it is trying to force companies to tell customers exactly how much the service charge for premium lines is. Under this rule, customers will have to be told what the calls fee is when they switch to a new bank or energy supplier.

On the face of it, that's great news – slightly tempered by the fact Ofcom has given companies at least 18 months to comply. That leaves them a year and a half more to rake in excess hidden profits from us just because we may need to, on occasion, call the company we're using.

And let's not forget that they are almost certainly already making a fat profit from supplying banking services or gas or whatever.

Which brings me to the other reason why the changes may not help us: they won't stop phone firms increasing the prices of these calls. It's estimated that some premium rate numbers have gone up by more than 400 per cent over the last two years.

So I'd urge anyone calling an expensive company line to find a cheaper way to get in touch. For instance, the website www.saynoto0870.com lists cheaper alternatives for 0500, 0800, 0808, 0842, 0843, 0844, 0845, 0870, 0871, 0872 and 0873 numbers.

Then I'd like the regulator to adopt a new way of charging for these premium numbers. I reckon there is a simple solution which could clear up charges confusion for good.

It's this: make all 08 numbers relate to their cost. So while all 0800 numbers would be free – from any phone – 0801 numbers should be 1p a minute. That would make 0802 numbers 2p a minute, and so on. The popular 0845 numbers would clearly be charged at a rip-off 45p a minute while 0870 would be an even greater example of blatant profiteering.

You could take it further to premium rate 09 numbers, which are used by the likes of entertainment chat lines and TV reality shows. If 0900 numbers were set at £1 a minute, then 0901 would be £1.01 and so on.

This proposed change may not be easy to introduce but surely 18 months is time enough to switch to a more sensible, consumer-friendly system of numbers?