423 Hounslow to Heathrow Airport Terminal 5 via Hatton, Harlington

Operated by London United. First bus 03:20, last bus 00:50. 115 journeys on weekdays. Fares: £1.75 flat — more.

Night bus — overnight departures 22:01–07:00. Every night. Nights are the night you set out on, so a 01:30 bus on Saturday morning counts as Friday. All night buses.

Wanted a different 423? 6 other bus routes are numbered 423 elsewhere in the UK — see every 423 bus timetable by area.

Each column is one journey, headed by the time it sets off. Times are shown at the route's main timing stops — buses serve all stops in between. Switch a table to All stops for every stop it calls at, or open a stop's own page for live departures there.

Christmas & bank holidays

These dates are not the usual timetable for the day they fall on. They come from the operator’s published data, which for Christmas and New Year is often late or incomplete, so check with London United before you travel. Everything above is an ordinary week.

Not published yet: Christmas Eve, Christmas Day, Boxing Day, 27 December, 28 December, 29 December, 30 December, New Year's Eve, New Year's Day and 2 January. Operators often publish festive timetables only a few weeks ahead, so check again nearer the date.

Route map

All stops on route 423

How busy is route 423?

2.11m passenger journeys were recorded on route 423 in 2024/25 across 613,380 kilometres operated.

Millions of passenger journeys per financial year, from Transport for London's published bus statistics. A passenger journey is one boarding of one bus — someone commuting five days a week makes ten of them, so this is not a count of people. Years marked 53w ran 53 weeks rather than 52, so they sit about 2% high against their neighbours. TfL changed how boardings were estimated in 2017 and restated 2016/17 on the new basis; the chart uses the restated figure, so years before 2016/17 are not exactly comparable with those after. Route-level totals do not sum to TfL's network figures, which carry separate adjustments. Powered by TfL Open Data. Compare every London route →

Towns & areas on this route

Frequently asked questions

Timetable data from London United via the DfT Bus Open Data Service (London feed). Route names, stop sequences and map geometry come from TfL Open Data. Check before you travel — services can change at short notice.