Black cab is the official London taxi. There are also licensed minicabs.
Getting a cab
You can hail a black cab on the street. For crowded areas it is faster and easier to hire a cab from a designated taxi stand (rail stations, airports, major tourist attractions etc.). You can also book a taxi by phone. You can also hire a cab or an official minicab via a Cabwise app.
Always use only official taxi.
While black cabs can be hailed on the street, licensed minicabs can only be booked by phone or an app - they cannot be hailed on the street. Beware of any drivers approaching you and offering taxi service - it might be dangerous.
The minimum fare for a black cab is £2.40. Please check TFL website for taxi fares in London - it will give you a good idea on how much the taxi is.