BBC News Online picks up the receiver to check out the new numbers.
With the launch of a raft of new companies, customers have been promised the prospect of cheaper directory enquiry calls - but the sums could prove confusing.
BT is scrapping its fixed 40p charge for the service and replacing it with a time-based one.
Callers will be charged an initial 25p per call and another 30p for every minute they spend connected to the service.
The Number UK is charging 49p and 9p per minute, while Conduit offers the same rate per minute but with an initial charge of just 39p.
And One Tel charges a flat rate of 35p per call.
So far, so complicated - and it gets worse.
Some new numbers
BT: 118 500
British Gas: 118 511, 118 411
Orange: 118 000
One Tel: 118 111 and 118 211
Opal Telecom: 118 114
Telegate: 118 866
The Number UK Ltd: 118 118
Some services will simply tell you the number you require - but others will offer to connect you without the need to redial.
Callers can also now choose between a bewildering array of new services beyond just residential and business numbers.
Given the variety of call charges, it seems wise that callers should keep an eye on the speed at which their call is dealt with against the cost per minute.
Phone for the telephone number of a cinema and you could be offered information about the films that are showing there, a list of alternatives in the same area and even a guide to what is on television in case you can't make up your mind.
Cost of one-minute enquiry
One Tel: 35p
Conduit: 48p
BT: 55p
British Gas: 55p
Telegate: 55p
The Number UK Ltd: 58p
And if you want to book a restaurant for the way home, find out how your shares are doing or even whether you have won the Lottery, simply dial 118 followed by ... well, the choice is yours.
At least that's the theory - but when BBC News Online road-tested eight of the new numbers, six of them failed to offer anything more than telephone numbers and "call completion".
Only The Number UK and British Gas were able to offer event listings or classified business searches by category and area.
The Number also offered directions to the cinema - but to find out where and when the new James Bond film, Die Another Day, was showing in south London took four minutes and 47 seconds at a cost of about 94p.
And to obtain the same information from British Gas cost about £2.05 and took six minutes.