Update: 29 June 2015: This news story was originally published in February and updated in May, but since then some prices may have changed, and it's likely these will change again due to new rules coming into force from 1 July 2015. Despite this, these numbers will remain expensive to call.

The firm 118 118's adverts once gave the nation a great giggle – yet its rip-off prices are no laughing matter. Its business model is, in my view, a near moral disgrace – and I'm not even talking about the fact it has set up a payday lender.

For many the idea of calling 118 numbers is ancient history, and that's part of the problem – those who do either don't have the internet and thus are likely already information disenfranchised, or are calling as a one-off, and the system seems designed to entrap for that one-off "in a rush I'll just call" moment.

I recently received this shocking tweet from a site user

" @martinslewis Just been charged £183 for one call via @118118 @O2 How can this be right?"

So I nipped to 118 118's website to check it out and see its pricing structure. It took much longer to find than I expected, but when I eventually found it, here's what it said…

"Calls to 118 118 cost £1.88 per call plus £2.57 per minute (minimum 60 second charge) from most landlines."

It then explains it could be more from mobiles.

So even at its cheapest, the minimum cost is a staggering £4.45 even if you connect then slam the phone down. And when it says from a mobile it could be more, boy is it, I checked and from O2, it's £5 a minute for a minimum of 60 seconds, so just getting through costs a fiver.

The way people get caught out…

While the above price is expensive, it is possible to justify it by saying it is offering a service and that has a cost. While I think it's overpriced, for the sake of argument let's accept it for now.

The underlying problem though is much more vicious. What it does when you call is offer to "to connect you through". This sounds innocuous, and I'd lay a safe bet that's what my tweeter did, but then when it does connect you though, you're still paying 118 118's rates, in other words £2.57 a minute on BT, or £5 on O2 (other mobiles are similar).

My quick maths suggests my questioner made a call of around 37 minutes in total, and that came to £183.

Yet had he put the phone down and just dialled the number – and to be fair it does text you the number if you're calling from a mobile – as the table below shows, it would've been a fraction of the price.

Cost of a 35 minute call

Calling Via 118 118 on BT Via BT direct Via 118 118 on O2 Via O2 direct
Local rate number £92 £3.50 (i) £175 £16 (i)
0870 number £92 £3.50 (i) £175 £7
USA landline N/A £7 N/A £35
Premium rate sexline (ii) N/A £36 N/A £70
Prices rounded to the nearest 50p. (i) Free if included in call plan (ii) Sexy121Chat.

Even though I've compared 118 118 to BT rather than the really cheap operators, you can see on the Call Checker that the price differences speak for themselves.

The call to 118 118 is seven times more expensive than calling even a premium rate sex line, and many magnitudes more than just making the call yourself.

Of course many don't use directory enquiries anymore, but it only takes once to be caught

These days there are many ways to find numbers without resorting to making a call, and that's almost the problem. As most people will be calling few and far between and 118 118's advertising is so prevalent, it's the first one that comes to mind, and as my tweeter found out one mistake can cost a fortune.

There are cheaper options if you want to call a 118 number, eg, the free 0800 118 3733 (you will pay from mobiles but can avoid this via our Free 0800 Calls from Mobiles guide), which makes money from advertising, or just the straight cheapest 118 990, which is 35.5p per call plus 10.2p per minute from a BT landline (varies from a mobile).

Cost of various directory enquiries services

Calling Via BT Via O2 2-min call via BT 30-min call via BT
BT - 118 500 £1.99/call + £2.46/min £5/min £6.91 £75.79
Nine Telecom - 118 990 £0.36/call + £0.11/min £5/min £0.58 £3.66
O2 - 118 402 £0.70/call + £0.60/min £1/min £1.90 £18.70
Post Office
- 118 855 (i)
£1.02/call £5/min n/a n/a
Talk Talk
- 118 111
£1/call + £1/min £5/min £3 £31
The Ask
- 118 000
£0.50/call (incl first min) + £0.21/min £5/min £0.71 £6.59
The Number
- 118 118
£1.88/call + £2.57/min £5/min £7.02 £78.98
Yell - 118 24 7 £1.53/call + £1.84/min £5/min £5.21 £56.73
118 Free - 0800 118 3733 (i) Free - has ads £0.21/min n/a n/a
Prices rounded up to the whole pence. All providers continue to charge the same rate if you are connected through to the number you're looking for. (i) Does not provide a connect-through service, it will only give you the number to call yourself.

This type of behaviour really does make you question whether deregulation worked. In our recent renationalisation poll, 62% of those who expressed a preference wanted directory enquiry services renationalised. Whether we go that far, or just ban such extortionate call connection costs, 118 118s current model needs changing.