Black cabs. Though there has never been law requiring London's taxis to be black, they were, since the end of the Second World War, sold in a standard colour of black. This, in the 1970s gave rise within the minicab trade to the nickname 'black cab' and it has become common currency.

The iconic silhouette of the London Black Cab (Hackney Carriage) is a result of strict "Conditions of Fitness" regulations that have existed for over a century. One of the most famous requirements is a 25-foot turning circle, designed so cabs could easily navigate the tiny roundabout in front of the Savoy Hotel. This requires a specific chassis and steering geometry that results in their tall, boxy shape. The "tallness" was originally mandated so that a gentleman could sit inside comfortably while wearing a top hat. In 2026, the modern electric model (LEVC TX) retains this shape to maximize interior space for accessibility—every black cab must be wheelchair accessible by law. The "Black" color was never a legal requirement; after WWII, the Austin FX4 was simply mass-produced in black as the cheapest, standard option, and the color eventually became an inseparable part of the London brand.