So most black cab drivers show less than what they earn in order to avoid paying more income tax and v.a.t. Their salaries obviously depend on the amount of time they spend behind the wheel driving around and they don't always take every customer they see. They also often cruise around without their lights on inorder to refuse any customers. Most black cab drivers in London do live in rather nice houses. Tax officials have very little to do. They often look at their mileage but that can easily rebutted by saying they also use it for private use. As you can see, black cab drivers in London do earn a lot and pay a similar amount of tax to someone trying to make ends meet. Unfortunately this is not unique to black cab drivers. A lot of people in UK who own their businesses evade tax. That is not to be confused with avoiding tax. The former is a criminal offence and punishable by law, the latter is completely legal. So most London black-cab drivers earn in excess of £50k-£60k a year.