See
http://www.autoclassic.com/features/...1901-1920.html
"1904 The firm, then known as Autocar & Accessories Limited, produced a commercial vehicle known as the Autocarrier. This was a 5.6 hp air cooled single cylinder tricycle built as a delivery vehicle – which proved successful."
..."1907 A passenger-carrying version of the Autocarrier was made, known as the Sociable. Its simple and practical design ensured its production until 1915. The abbreviation AC was used for the first time and in November a new company was formed, Autocarriers Limited, taking over Autocar & Accessories but with Weller and Portwine still as Directors."