As part of the privatisation of the National Bus Company, West Yorkshire was sold in a management buyout to the AJS Group in 1987.

This new company absorbed all the local services in and around Keighley, but West Yorkshire Road Car Co kept its longer distance routes.

When the National Bus Company was formed in January 1969, it was operating three services in York: National Bus, West Yorkshire Road Car Co (rural areas, Leeds and the East coast), and the York-West Yorkshire joint service.

In April 1954 the fleet was renumbered using type identification letters in addition to sequence numbering.

Over the years, several exceptions to these rules evolved, including DX (Double deck eXperimental), used to denote Bristol Lodekka buses, SUG/EUG/CUG (Single-decker/Express/Coach Underfloor-engined Gardner), SMA/SMG (Single-decker Mid-engined Albion/Gardner), SRG (Single-decker Rear-engined Gardner), VR (Vertical Rear-engined – Bristol VR type) In October 1971 the fleet was again renumbered and the class identification letters disappeared as the fleet identifiers once again reverted to purely numerical system.

In April 1958, vehicles were fitted with small coloured discs next to their fleet number to identify their main garage.

[9] Sub-garages inherited the colour of their parent garage, however Keighley- and York-West Yorkshire vehicles were not fitted with the discs as they were already identifiable by the K- or Y prefix.