A Soho walk-up is a flat in Soho, London, United Kingdom, that is used by a female sex worker for the purposes of prostitution.[1] The flats are located on the upper floors of buildings in Soho's red light district, often above shops, and accessed by a staircase from a door on the street.[1] They form a distinctive way of working that is characteristic of the sex industry in Soho, originating in the 1960s[2] and declining during the 21st century.[1]