Asok BTS Bangkok: Exits, MRT Transfer and Terminal 21

Asok BTS (station code E4) is the Sukhumvit Line stop where the skytrain meets the MRT Blue Line, and for most visitors it means one thing: take Exit 3 for the underground MRT Sukhumvit station, or Exit 1 for Terminal 21. Both stations sit on the same junction of Sukhumvit Road and Asok Montri Road, linked by a footbridge, but they are run by different operators, so you scan out of one system and into the other. This guide covers the exits, the transfer step by step, fares and hours (checked 9 October 2026), and what is within a short walk of the crossing.

What is Asok BTS station?

Asok BTS opened on 5 December 1999 as part of the Sukhumvit Line and is at the Sukhumvit Road and Asok Montri Road intersection, in Watthana and Khlong Toei districts. Its neighbours on the line are Nana and Phrom Phong.

The site has some history: it once held Si Krung, a film studio and cinema founded in 1927. Wikipedia describes the stretch to the west as a continuation of the Nana entertainment zone and the stretch to the east as a dense commercial district with skyscrapers.

The MRT side is MRT Sukhumvit (code BL22), which opened on 3 July 2004 directly below the same junction and is run by Bangkok Expressway and Metro (BEM). Wikipedia calls it one of the busiest stations on the MRT network, and it recorded 9,627,729 passengers in 2021, against 5,542,521 for Asok BTS in the same year.

Which Asok BTS exit goes where?

Exit numbers matter here because the station spreads across a busy junction and the wrong staircase can put you on the wrong side of Sukhumvit Road. Wikipedia lists four exits:

• Exit 1: Sukhumvit Soi 19, a bus stop for services toward Phrom Phong, and the M floor of Terminal 21.
• Exit 2: a bus stop for services toward Nana, on Sukhumvit Soi 12.
• Exit 3: the MRT Sukhumvit station, Asok Montri Road, the Siam Society, Srinakharinwirot University and the M floor of Terminal 21.
• Exit 4: Sukhumvit Soi 14 and Soi 16, Ratchadaphisek Road and Benjakitti Park.

One independent station guide lists six exits and places the Westin Grande Sukhumvit and Sofitel Bangkok Sukhumvit at Exit 5, and the Continent Hotel Bangkok and Jasmine City Hotel at Exit 6. Because the two sources differ, follow the numbered signs on the platform stairs for those hotels rather than relying on one list.

Why do sources disagree on the Terminal 21 exit?

Terminal 21’s own “How to Go” page names BTS Asok Station Exit 1 and MRT Sukhumvit Station Exit 3. Wikipedia lists both BTS Exit 1 and Exit 3 as routes to the mall’s M floor, and a station guide puts Exit 1 at Terminal 21 and Exit 3 at the MRT and the Grande Centre Point Terminal 21 hotel. In practice, take Exit 1 if you only want the mall, and Exit 3 if you also need the MRT. Follow the signs on the day.

How do you transfer from BTS Asok to MRT Sukhumvit?

Use Exit 3 and cross by the footbridge that links the two stations. Wikipedia describes the footbridge as a skywalk that joins Asok station to MRT Sukhumvit. A separate article on this site puts the Asok to Sukhumvit MRT transfer at roughly 3-4 minutes gate to gate (see BTS and MRT interchange transfers).

Step by step, from the BTS:

1. Tap out at the Asok gates and follow the signs for Exit 3.
2. Follow the signs for MRT Sukhumvit along the skywalk, then go down into the station entrance.
3. Buy a ticket or tap a contactless card at the MRT gates. The MRT is a separate system, so a BTS ticket or card balance does not carry over.
4. Check the platform signs before descending. Platform 1 serves trains toward Lak Song, and Platform 2 serves trains toward Tha Phra via Bang Sue.

From the MRT, the overhead signs point to “3, BTS Asok Station” at the top of the exit stairs, with an escalator and a lift beside the stairs. That is the route back up to the skytrain.

What does MRT Sukhumvit look like inside?

The station is underground on three levels. Wikipedia lists B1 as the level with the exits and an underground mall, B2 as the concourse with ticket machines, and B3 as the platforms. There are three exits and three elevators. The platform is an island layout with two central platforms.

The station posts a locality map that shows the three exits, the lifts, Terminal 21, the Siam Society, the Westin Grande Sukhumvit, Interchange 21 and the Sheraton Grande Sukhumvit. It is worth a minute if you arrive underground and are not sure which side of the road your hotel is on.

How do you pay on the MRT side?

Single-journey tickets are valid only on the day of purchase, and the ticket machines take cash only, in baht coins and banknotes. Contactless payment is available at the gates for Visa or Mastercard credit cards from any bank, and for debit cards from Krungthai Bank or UOB only. A poster at the station shows the same card rules. The MRT also has a stored value card. For the BTS side, a station guide recommends a Rabbit card with enough value, or a single-journey ticket from a machine, for the earliest and latest trains, because the ticket office cannot sell tickets or add value outside service hours.

What do fares and hours look like at Asok?

Sample BTS fares from Asok, from a station guide checked 9 October 2026 (rate used: 33.5 THB per USD, Trading Economics, 9 October 2026):

MRT Blue Line fares were revised to 17-44 THB (~USD 0.51 to 1.31) from 3 July 2026, according to Nation Thailand. A one-station trip costs 17 THB and a trip of 12 or more stations costs 44 THB. Senior citizens pay half fare, and children no taller than 120 cm are exempt. Fares change, so confirm at the station before a long trip.

BTS hours from the same station guide: the first train from Asok leaves at 05:36 in both directions. The last train toward Kheha leaves at 00:09 and the last toward Khu Khot at 23:53, with trains every 2.5 to 8 minutes. The MRT Blue Line runs daily from about 06:00 to midnight. Times shift with timetable updates, so check the boards on the platform.

For the wider network, see the BTS and MRT guide, and for other stations where the two systems meet, the interchange stations guide.

What is at Terminal 21 and how do you get there?

Terminal 21 is at 88 Sukhumvit Soi 19, North Klongtoei, Watthana, Bangkok 10110, and links to both stations by skywalk. It opened on 11 October 2011, and its retail area has 10 stories. Each floor is decorated after a different city or location, including Rome, Paris, Tokyo, London, Istanbul, San Francisco and Hollywood, which Wikipedia describes as a one-floor-one-themed mall.

Both BTS Exit 1 and Exit 3 lead to the M floor, and the signs on the escalators read “Arrival at Level M” with Paris as the theme. The complex also holds an SF Cinema and a Gourmet Market, and a hotel tower rises behind the mall.

Terminal 21’s directions also list bus routes 2, 25, 38, 40, 136, 185, 501, 508, 511 and 513. Check the mall’s own channels for opening hours on the day you plan to go.

What else is within walking distance of Asok?

Sukhumvit Road is the spine of the area. The sois run in numbered order from west to east, with odd numbers on the north-east side and even numbers on the south-west side. Soi 21 is also called Asok Montri Road, and Ratchadaphisek Road crosses Sukhumvit Road at the junction. Wikipedia notes that Soi 12 holds a Koreatown, and that The Emporium, an upscale shopping centre, sits on the road.

Near the junction, station guides and Wikipedia list:

• Siam Society and Kamthieng House. A listing places Kamthieng House at 131 Soi Sukhumvit 21 (Asok Montri), about five minutes on foot north of Asok BTS or MRT Sukhumvit, with the Siam Society a couple of hundred metres further north. The listing says the museum is closed for restoration until further notice, so contact the Siam Society before you go.
• Benjakitti Park. Exit 4 is the exit station guides list for the park. Most sources give daily opening from about 05:00 to 21:00 and free entry. After its 2022 expansion the park covers 72 hectares and has elevated walkways.
• Srinakharinwirot University and the Embassy of India, both listed near MRT Sukhumvit.
• Offices and hotels. Interchange 21 Tower and Sheraton Grande Sukhumvit are listed near MRT Sukhumvit.

Wikipedia also notes that Asok is known for its rush-hour traffic.

Which hotels are near Asok BTS?

A station guide lists these hotels by exit: Grande Centre Point Terminal 21 at Exit 3, Solaria Nishitetsu Hotel at Exit 4, and the Sheraton Grande Sukhumvit at Exit 2 or 5. The Westin Grande Sukhumvit and Sofitel Bangkok Sukhumvit are listed at Exit 5. This is a list of what sits near each exit, not a ranking; more options are in hotels in Nana, Asok and Sukhumvit. For a wider comparison of areas, see the where to stay in Bangkok guide.

What mistakes do travellers make at Asok?

• Assuming one ticket covers both systems. MRT guidance states that other connected train systems need separate tickets, so allow for a second fare on any trip that crosses between them.
• Using the wrong exit. Some sources say Exit 1 and Exit 3 both reach Terminal 21, but only Exit 3 leads to the MRT. Check the sign before you tap out.
• Arriving at midnight with no value on a card. The BTS ticket office closes at 24:00 and cannot add value outside service hours.
• Paying the MRT with the wrong debit card. Only Krungthai and UOB debit cards work for contactless entry, so carry a credit card, a stored value card or cash.
• Planning around old opening times. Hours, fares and exit routes change. Treat the dates in this article as the last time we checked, and confirm anything time-sensitive on the day.

Summary

Asok BTS and MRT Sukhumvit work as one interchange in practice, even though two operators run them. Use Exit 3 for the footbridge to the MRT, Exit 1 or Exit 3 for Terminal 21, and Exit 4 for Benjakitti Park. Budget a second fare for the MRT, check platform signs for direction, and verify exit numbers and hours locally on the day.