The service, developed by mobile systems supplier Zingo, is one of the first widespread applications of location-based technology, which has been available in some form for years but has been adopted by few businesses.
Vodafone, T-Mobile and 02 have already signed up to the service, which locates mobile phone users requesting a London taxi and directs the nearest cab to them without any intermediary call centre. Orange and 3 are in discussions about adopting the system.
Zingo, a subsidiary of London taxi manufacturer Manganese Bronze Services, is confident the service, which has been in development for two years, will prove successful.
"There are 20,000 black cabs in London, and a total of 100 million cab journeys are taken each year. We expect to get a good proportion of these using our service," said Mark Fawcett, managing director at Zingo. "User feedback from initial trials has been very positive and we see Zingo being the first port-of-call when people want a cab."
John Thomas, chairman of the London Taxi Drivers' Association, welcomed the launch of the Zingo service.
"Anything that puts more people on the back seats of cabs is a good thing," he said. "It should do great things for suburban drivers and also those without radios. Two thirds of drivers do not use radios, preferring 'street work', and Zingo should be particularly useful to them."
Zingo hopes to launch the service in other major UK cities in the near future, Fawcett said. It has also had interest from other companies interested in using its technology, he added.