Route 400 commenced operating as a limited stops service between Bondi Junction and Burwood stations on 17 July 1989.

On 23 June 2002, short workings between Bondi Junction and Rockdale station were renumbered 410.

Initially all trips covered the full route, in its last years, up to half the journeys were short workings between Bondi Junction and Westfield Eastgardens.

Route 400 was initially operated by a fleet of ten dedicated Pressed Metal Corporation bodied Mercedes-Benz O305 buses.

These were selected as they were fitted with dot matrix displays at a time when most of the fleet still had calico blinds and, as the route would cross regions, none had all of the required destinations.