The Austin London Taxicab used a modified Austin Heavy Twelve-Four chassis clothed with new bodies designed by London's largest taxicab retailer and dealer Mann & Overton, and made for them by London coachbuilders.

Will Overton, director of the car dealership Mann & Overton, had been selling Unic taxicabs in London since 1906. In 1924 their business with its French-made Unics had provided almost 80% of the new taxicabs bought in London. In 1925, with effect from 1 May 1926, McKenna duties were imposed on commercial vehicles to protect UK manufacturers from imports and in spite of Unic's local assembly operation in Cricklewood, opened in 1928, it was no longer possible to supply London with French Unic taxicabs at an acceptable price. So William Overton approached Herbert Austin about modifying the Heavy Twelve-Four hire car chassis so that it would comply with the London Conditions of Fitness. It had been announced in 1927 that those regulations would be lightened with effect from 1928. In view of the easing of police regulations and the enormous gap in the market left by imported vehicles Austin duly modified their hire-car chassis to suit, and Mann & Overton arranged for their catalogued three standard bodies made in Greater London by: Strachan or Vincent or – for £5 more – Jones.

From 1930 to 1934 this first Austin London taxicab was colloquially known as the High Lot or Upright Grand. On a new chassis and thereby much lowered its appearance was revised in 1934 and it was renamed by Austin the Low Loading taxi.^[2]

Previously Austin had only provided hire car chassis not troubling to make major amendments to that chassis to comply with Metropolitan Police regulations for London taxicabs.^[3]

• 1934 Austin Taxi, body by Jones Bros

• Shaftesbury Avenue from Piccadilly Circus, in the West End of London, 1949
• London, 1946
• London, 1941
• London, 1941

After the Second World War, Mann & Overton decided that it needed a more up-to-date design. So it was agreed that Austin would supply the engine/chassis and Carbodies in Coventry the body, although it was actually designed by Austin's chief body designer Jim Stanfield. In 1948 a new Austin taxi appeared on the streets called the FX3. It was soon the market leader. Although in 1952 a diesel engine from Perkins Engines was available as a conversion, by 1954 Austin was producing their own 2.2 litre diesel engine as a factory fit. Also made by Austin and Carbodies was the hire car FL1 which was almost identical but lacking luggage space by the driver, having instead a bench seat, and there was no roof sign.

• List of Austin motor vehicles § London Taxicabs