Seoul Subway Guide: Lines, Transfers, and Apps

The Seoul subway is one of the best urban rail systems in the world — clean, cheap, punctual, and so extensive that for most trips it beats taxis on both time and money. It’s also genuinely enormous: more than twenty lines when you count the suburban and light-rail extensions, over 700 stations, and signage that switches between four languages. This guide covers everything a visitor actually needs: how the network is organized, what it costs, how transfers work, which apps to use, and the small habits that make you ride like a local instead of a lost tourist.

Getting oriented: how the network is organized

The core of the system is nine numbered lines — Line 1 through Line 9 — each with its own color. Beyond those, a constellation of named lines fills in the gaps: the Gyeongui-Jungang Line running east-west along the Han River, the Sinbundang Line shooting south to Pangyo and Gwanggyo, the Airport Railroad (AREX) linking Incheon Airport to Seoul Station, and a dozen others. Don’t try to memorize the map. Learn the handful of lines that matter for your itinerary and let an app handle the rest.

A few lines carry most of the tourist load, so it’s worth knowing their personalities.

Line 2: the green circle

Line 2 is Seoul’s Yamanote — a loop that hits Hongdae, City Hall, Euljiro, Gangnam, and Jamsil. If your hotel is anywhere on it, you’ve won the accommodation lottery. It’s also the most crowded line at rush hour, which is exactly when you shouldn’t be carrying a suitcase on it.

Line 4: the north-south tourist spine

Myeongdong, Dongdaemun, Chungmuro for the palace area, and Seoul Station connections — Line 4 (light blue) strings together a remarkable number of first-trip destinations.

The Airport Railroad (AREX)

Two services share the AREX tracks: the all-stop train, which costs about the same as the subway and takes roughly an hour from Incheon Terminal 1 to Seoul Station, and the express train, nonstop, about 43 minutes, with reserved seats. The all-stop train is fine; the express is worth it with luggage or jet lag.

Fares and payment

Seoul’s fares are distance-based and, by global-city standards, almost embarrassingly cheap. You tap in with a T-money card (see our separate T-money guide for buying and topping up), and the gate calculates everything.

Three payment notes worth knowing:

1. T-money is the default. Every gate, every line, every city bus takes it, and it’s the only method that reliably gives you transfer discounts.
2. Foreign contactless cards work on many gates in Seoul as of 2026, but not on all suburban lines, and they don’t always link transfers correctly. Treat this as a backup, not a plan.
3. Skip single-journey tickets. The vending machine flow — buy, deposit, ride, then queue again at a refund machine to get your ₩500 back — wastes ten minutes per trip.

Rush-hour honesty: fares don’t change at peak times, but your experience does. Weekdays 7:30–9:00 and 18:00–19:30 on Lines 2 and 9 are a full-contact sport. With luggage, budget an extra half hour and take the less crowded option even when the app says it’s four minutes slower.

Transfers: the rules of the game

Transfers inside the subway network are free — you walk from one line to another behind the gates and never tap. The rules that trip visitors up are the ones involving buses and exits:

• Subway ↔ bus transfers are discounted, not free. Tap out of the subway, board a bus within 30 minutes, and the system charges you as one continuous journey. This only works with the same T-money card, and only if you tapped out properly.
• Leaving through the gates ends your trip. Some stations have exits on both sides of the tracks but no crossing corridor behind the gates — leave through the wrong gate line and getting to the other side means paying again. Check the yellow overhead signs for your exit number before passing the gates.
• Transfer corridors can be long. A “transfer” at Express Bus Terminal or Jongno 3-ga can mean a ten-minute walk with stairs. Apps show realistic transfer times; believe them.

Some transfers are famous enough to have nicknames — the marathon between Line 9 and Line 3 at Express Bus Terminal, or the vertical hike at Itaewon. When two routes look equal, pick the one with fewer transfers. Your feet will thank you.

Apps: what to install and what to skip

Google Maps does not do turn-by-turn transit routing well in Korea — mapping data export restrictions mean it can’t. Locals use two ecosystems, and you should install both:

• Naver Map — best overall for foreigners: full English interface, live subway arrivals, exit-number guidance, and walking directions that actually work.
• Kakao Metro — a dedicated subway app: tap your start and end stations on the map, and it tells you the fastest route, the transfer stations, and — crucially — which car to board for the quickest transfer.
• Papago — not a transit app, but you’ll want it when a service announcement scrolls by in Korean only.

One habit that changes everything: Koreans navigate by exit numbers. Nobody says “meet me at Gangnam Station” — they say “Gangnam Station, Exit 11.” When a friend, a hotel, or a restaurant gives you directions, they’ll look like this:

Hongik Univ. Stn (Line 2, AREX, Gyeongui-Jungang)
→ Exit 3, walk straight 200 m
→ left at the GS25 convenience store
Sinsa Stn (Line 3) → Exit 8 → 5 min walk

Save the station name, line, and exit number together. An address without an exit number in Seoul is only half an address.

Riding etiquette

Nothing here will get you in trouble if you slip, but doing these makes you invisible — which on public transit is the goal:

• Stand right, walk left on escalators (though officially you’re asked not to walk at all).
• Don’t sit in the priority seats at car ends, even when the car is empty. Locals leave them vacant for elderly passengers as a matter of principle.
• Pregnant-passenger seats — the pink ones mid-car — same rule, and yes, locals really do leave them empty.
• Keep phone calls short and quiet. Texting is universal; a loud speakerphone call marks you instantly.
• Line up at the door markings on the platform floor and let passengers off first.
• Backpacks come off in crowded cars — hold yours low, or use the overhead racks.

None of this is written on any sign in English. All of it is noticed.

First and last trains

The Seoul subway does not run all night. First trains leave terminal stations around 5:30, and last trains start their final runs between 23:00 and midnight depending on the line and direction — importantly, a “last train” may finish short of the end of the line, so the last train that gets you home may leave earlier than the timetable’s last departure.

If you’re out in Hongdae or Gangnam past midnight, your options are the N-series night buses — T-money works, routes shown in Naver Map — or a taxi hailed through the Kakao T app. Taxis after midnight carry a late-night surcharge, and demand around 2 am in nightlife districts is brutal; either leave by 23:30 with the subway crowd or commit to staying out until dawn like everyone else.

Luggage, strollers, and step-free routes

Every station has elevators, but not every exit has one, and at big interchange stations the elevator can be a long way from the exit you actually want. If you’re traveling with a suitcase, a stroller, or limited mobility, three things help:

• Look for the elevator icon on the station map posted by the platform stairs — it marks which exit the elevator serves. Naver Map can also route you step-free if you set the option.
• Use the wide gate. Every gate line has one extra-wide gate for wheelchairs and luggage, usually at the far end near the station office. Nobody minds if you use it with a suitcase.
• Transfer stations are the hard part. An accessible station doesn’t guarantee an accessible transfer; corridors between lines sometimes rely on stairs even where both platforms have elevators. When in doubt, a route with one fewer transfer is nearly always the better step-free choice, even when it’s slower on paper.

Restrooms, while we’re on station practicalities, are free, generally clean, and usually located outside the gates — another reason to check the station map before you tap out, since re-entering costs a new base fare if you exit on the wrong side. Larger stations also hide small pharmacies, bakeries, and phone-accessory stalls in their underground arcades; the underground shopping streets at Express Bus Terminal and Jamsil are destinations in their own right.

Lockers are another quiet lifesaver. Most medium and large stations have banks of storage lockers (look for “T-Locker”) that take T-money or cards, from about ₩2,000 for a small locker for a few hours. Dropping your bags at a locker near your last sightseeing stop, rather than hauling them across the city, is a move locals use constantly.

Common first-week mistakes

A short confession list, collected from every visitor I’ve ever hosted:

1. Boarding the right line in the wrong direction. Platform signs show the next station and the terminal station — check the terminal name against your app before boarding, not after.
2. Confusing express and local trains. Line 9 and the Gyeongui-Jungang Line run express services that skip stations. If your station is small, make sure you’re on an all-stop train — express trains are marked in red on the platform displays.
3. Sprinting for a closing door. Trains run every three to five minutes at most hours. There is always another one. The person holding the door open with a foot is never a local.
4. Trusting the station name too much. Some names repeat across systems or differ from the neighborhood name — the area around City Hall Station is Jung-gu, and “Seoul Station” the railway terminal is a different beast from the subway stops that share its name. Navigate by line number plus station, not station alone.
5. Tapping the card twice at the gate. If the gate beeps an error, don’t tap again on the next gate — find the station office window. Double-tapping can charge you a second base fare, and the attendant can fix a mis-tap in seconds.

A one-week starter kit

If you only remember five things from this guide:

1. Buy a T-money card at the airport convenience store and load ₩30,000.
2. Install Naver Map and Kakao Metro before you leave the airport WiFi.
3. Navigate by station + line + exit number, always.
4. Avoid Line 2 and Line 9 at weekday rush hour with luggage.
5. Know your last train home — and the N bus that backs it up.

The subway is where Seoul actually happens: commuters sleeping standing up, ajumma (middle-aged women) with hiking gear at 6 am, students rehearsing choreography in the transfer corridors. Ride it enough and the city stops feeling foreign — it starts feeling like a very large neighborhood with excellent signage.