Documents shown by Uber to investors in the present fundraising round estimate that the company's gross revenue is $10 billion globally. Uber allows customers to hail minicabs using a smartphone app that automatically calculates the distance they will travel and their fare. Bank accounts are debited at the end of each trip, meaning that no cash changes hands between passenger and driver. The app can be used in 12 cities in Britain. In February, Uber enlarged a fundraising round from $1.8 billion to $2.8 billion to sate investor demand. The company closed a $1.2 billion round in December last year that raised its valuation to $41 billion. This week Uber announced plans to launch UberPool, a carpooling service, in London. It is available in 15 cities around the world. Under the plans, from today, taxi users will be able to share journeys with strangers to cut the cost of fares.