The first five licensed minicabs are taking to the streets of London in an attempt to cut crime.
Over 200 sexual offences were committed in minicabs last year
There were more than 200 sexual offences committed in minicabs in London last year.
Every driver who is licensed will have been checked by the police and have a full clean driving licence.
The move is part two of a three-stage major transformation of the industry by London Mayor Ken Livingstone and Transport for London (TfL).
Minicab operators had to be licensed by October 2001, now the drivers are undergoing checks and next year their vehicles will need a licence.
Catherine Monk, London's first licensed female mini-cab driver, thinks the new laws are a good idea.
It is hoped the licenses will cut down on cab-related crimes
She told BBC London: "I think the customers will feel better getting into a cab knowing that they're with someone who's not going to hurt them.
"My daughter got into a cab and the driver was just so fast that she came home and was crying."
Ms Monk also said a driving test would be a good idea to raise standards.
In October last year Mohammed Akhtar, 28, of Watford Way, north-west London, was jailed for nine years for raping two women while posing as a minicab driver.
The Metropolitan Police are also launching a capital-wide police operation against illegal drivers.