Airport bus A21 to Kowloon

No single bus route is more quoted in Hong Kong travel forums than the A21. Operated by Citybus under its Cityflyer livery, it connects Hong Kong International Airport with Hung Hom by way of the spine of Kowloon: Kwun Chung, Jordan, Tsim Sha Tsui and, for most budget travellers, the stop that matters, Chungking Mansions on Nathan Road. For a visitor heading to a bed anywhere south of Mong Kok, the A21 is usually the cheapest ride that leaves you within walking distance of the door.

Fare, payment and where to board

The full fare is HKD 34.60 from the airport to any Kowloon stop, payable by Octopus card, by contactless bank card at the reader, or in exact cash. Children and seniors pay about half, and the fare is flat, so stepping off at Jordan or riding to the terminus at Hung Hom costs the same. Buses leave from the ground transport centre: follow the signs for buses to Kowloon after baggage reclaim, and the A21 bay number appears on the departure board. If you land without an Octopus card, this ride is a good reason to buy one, and the Octopus card guide explains the deposit and where the card pays for itself.

The stops that matter for a budget stay

Reading the route from the airport, the useful stops arrive in this order. Kwun Chung and Austin Road West serve the West Kowloon side and the Kowloon Station of the Airport Express. Jordan Road and Man Wui Street drop you at the edge of the guesthouse belt around Temple Street and Parkes Street, described in the Jordan and Yau Ma Tei guide. Then comes the stop every backpacker waits for, Chungking Mansions on Nathan Road, which serves the famous block itself, covered in the Chungking Mansions guide, and the guesthouses of the surrounding lanes. Further along, Mody Road and Chatham Road serve Tsim Sha Tsui East, useful for the newer hostels of that side, compared in the East against West guide. The terminus at Hung Hom serves the East Rail station and the university side.

Going back, and the night alternative

The return is equally direct: the airportbound A21 picks up along the same Nathan Road corridor, and the Chungking Mansions stop is again the one to wait at, with a practical rule of boarding ninety minutes before a midday check-in opens. When a flight leaves before 08:00, the first A21 will be too late, and when a flight lands after midnight, the A21 has gone to bed.

On both night edges, Kowloon belongs to the overnight routes, principally the N21 from the airport toward Tsim Sha Tsui, which follows a similar corridor through the small hours at a fare of about HKD 24, and to taxis, whose fare with tunnel tolls from the airport to Tsim Sha Tsui lands near HKD 300. Between the two, the night bus wins on price and loses on comfort, since it stops more often and takes longer, but it drops you in the same places. The other decision travellers face at the airport desk is bus against train, and the arithmetic of that choice, HKD 34.60 against the Airport Express fare plus a connection, is worked through in the A21 versus Airport Express comparison.

On board: the five point checklist

• Take the upper deck when you can: the ride crosses the Tsing Ma bridge and the container port, and the left side gives the better harbour and bridge views on the way in.
• One large suitcase travels free in the hold; keep day bags with you and clear of the staircase.
• Have the Octopus or bank card ready and tap once at the front reader; exact cash is the fallback.
• Watch the destination screen: every stop is announced in English as well as Chinese.
• Press the stop button as your street name appears, one block early rather than one block late.

Common A21 mistakes

• Cutting the journey figure too fine: seventy minutes is the empty road time, ninety is the honest one, and the tunnel approaches at rush hour can add more.
• Booking a cheap dawn flight and still counting on the bus: the first departures run around 05:30 from the airport, so earlier flights need the N21 or a taxi.
• Getting off one stop late at Chungking Mansions and walking back along the crowded pavement: the screen announces the stop name, so ride one more block only if you truly must.

The short answer

The A21 forgives small errors in a way a missed train connection does not, because the next double decker is typically ten minutes behind. For one or two travellers with a bed near Nathan Road, take it and pay HKD 34.60; take the Airport Express only for rush hour arrivals, groups that qualify for the train’s group fares, or the in-town check-in trick on the way home. The full comparison lives in the bus against train guide, and the bed at the end of the ride is chosen between the guesthouses of Chungking Mansions and the cheap hotels of Tsim Sha Tsui.