Various seating configurations were available, with Transport for London (TfL) specification models fitted with a central exit door.

Stagecoach subsidiaries outside London have ALX400s on long-wheelbase Dennis Trident 2 chassis, fitted with 51 seats upstairs (47 on later models) and 28 downstairs.

These buses have been used all over the UK, in major cities including London, Birmingham, Manchester and Newcastle.

[2][3] From its introduction until 2006, the Alexander ALX400 on the Dennis Trident 2 chassis was the favoured 2-axle double-decker bus model for the Stagecoach Group.

[6] Deliveries were made to Stagecoach operations across the United Kingdom such as in Oxford,[7] Devon,[8] Canterbury,[9] Cambridge,[10] and Kingston upon Hull,[11] among others.

[citation needed] Most of these featured 76 seat single door bodies although there were various seating capacities used on a small minority of rail and airport link services; Summerhill based AV 116-130 were built with dual-door bodies for use on the Airlink services.