West Yorkshire was formed in December 1927 but had its origins in the Harrogate Road Car Company, incorporated in November 1906. The name changed in 1924 to Harrogate & District Road Car and then again to West Yorkshire to reflect the wider area that was being covered as a result of the takeover of Premier Transport (Keighley) and Blythe & Berwick of Bradford. Many small operators were acquired in the 1926 to 1933 period and in 1932 the Company reached agreement to form a joint operating company with Keighley Corporation, that was called Keighley-West Yorkshire. A similar agreement, though not a separate company, was reached in 1934 to form York-West Yorkshire. SULs ran at various times from all depots except Bradford, Leeds, Wetherby and Scarborough.