When you use a subway and a bus during the same journey, properly tapping your transportation card can allow you to receive an integrated transfer fare instead of paying the full base fare for each ride separately. However, you may lose the transfer discount if you forget to tap your card when getting off a bus, exceed the transfer time limit, or board the same bus route again.
Many first-time users assume that transferring is always completely free. In reality, fares are calculated based on the total distance traveled from the first mode of transportation to the last. Even when a new base fare is not charged during a transfer, an additional distance-based fare or a fare difference between transportation types may still apply.
This guide explains how to transfer between subways and buses in the Seoul metropolitan area, how to tap your transportation card correctly, the permitted transfer time and number of transfers, and common situations in which transfer discounts may not apply.

1. How Subway and Bus Transfer Discounts Work

The Seoul Metropolitan Area Integrated Transfer Fare System connects buses and subways in Seoul, Gyeonggi Province, and Incheon and calculates the entire trip as one continuous journey.

The system applies to eligible Seoul buses, Gyeonggi buses, Incheon buses, and metropolitan subway lines when they are used consecutively with the same transportation card.

To receive a transfer discount, you must follow these basic rules.

Use a prepaid or postpaid transportation card instead of cash.
Tap the same transportation card when boarding and getting off.
Board the next form of transportation within the permitted transfer time.
Use one transportation card per passenger whenever possible.
Avoid boarding the same bus route or the same vehicle again.

Transfer Time Limit

The standard transfer time limit is generally within 30 minutes after tapping your card when getting off the previous bus or exiting the subway.

Between 9:00 p.m. and 7:00 a.m., the permitted transfer time is extended to within 60 minutes because buses and trains operate less frequently during late-night and early-morning hours.

The transfer time is determined by the moment you tap your card when boarding the next bus or entering the next subway station.

Maximum Number of Transfers

In the Seoul metropolitan area, you may generally transfer up to four times. Including the first ride, this means that up to five consecutive rides may be included in one integrated journey.

For example:

Board a local village bus.
Transfer to the subway.
Transfer to a city bus.
Transfer to another bus.
Transfer to another subway line.

Every transfer must meet the required card-tapping and time-limit conditions.

🔗 Check Seoul Metropolitan Transfer Discount Rules

2. How to Transfer Between a Bus and the Subway

Transferring from a Bus to the Subway

When taking a bus to a subway station, follow these steps.

Tap your transportation card on the reader near the front door when boarding the bus.
Press the stop button as you approach your destination.
Tap the same card on the reader near the rear or exit door before getting off.
Walk to the subway station within the permitted transfer time.
Tap the same transportation card at the subway ticket gate.
Tap the card again when exiting at your destination station.

The most important step is tapping your card when getting off the bus. If you fail to tap out, the system may not correctly record your travel distance or transfer starting time.

As a result, the subway ride may be treated as a separate journey, or an additional fare may be charged.

Transferring from the Subway to a Bus

When transferring from the subway to a bus, use the following sequence.

Tap your transportation card when entering the subway station.
Tap the same card when exiting at your destination station.
The transfer time begins from the moment you tap out of the subway.
Walk to the bus stop within the permitted time.
Tap the same card when boarding the bus.
Tap the card again when getting off the bus.

If you leave the subway station to eat, shop, or run an errand before boarding the bus, you may exceed the transfer time limit.

The transfer is determined by the time you tap your card on the next bus, not by the bus departure time.

Why You Must Keep Using the Same Card

If you pay for the first ride with a physical transportation card and then use a mobile transportation card or another credit card for the next ride, the system may identify the two payments as separate passengers.

You must use the same payment method throughout the entire transfer journey.

When using a mobile transportation card, do not switch to a physical card or another mobile payment option until the journey is complete.

🔗 Check Seoul Subway and Bus Fare Information

3. How to Transfer Between Subway Lines or Bus Routes

Transferring Between Subway Lines

At a subway transfer station, get off the train and follow the signs marked “Transfer” or “Transfer to Line...”

For example, when transferring from Line 2 to Line 3:

Get off at the transfer station.
Check the line number and color shown on the platform signs.
Follow the signs for Line 3.
Confirm the direction of your destination.
Board the next train without leaving the paid area.

Most subway transfers are completed through internal passageways without passing through an exit gate.

If you leave the station through a regular exit gate and enter another subway gate, the ride may be treated as a new journey.

Some stations have special transfer gates because of their structure or operating company. In those cases, use the gate clearly marked for transfers rather than a regular exit.

Transferring from One Bus to Another

To transfer between buses, tap your card when getting off the first bus and tap the same card when boarding the next bus within the permitted time.

A discount may not apply in the following situations.

You board the same bus route number again.
You get off and board the same vehicle again.
You fail to tap your card when getting off.
You exceed the transfer time limit.
You use a different transportation card.

For example, if you get off Bus 100 and then board another Bus 100 traveling in the opposite direction, the second ride may not be recognized as a transfer.

Similarly, if you briefly visit a convenience store or bank and then board the same bus route again, the ride is likely to be treated as a new trip.

Paying for Multiple Passengers with One Card

On some buses, one transportation card can be used to pay for several passengers after telling the driver the number of people.

However, group transfers may be restricted when transferring to the subway or another type of transportation.

When traveling with family or friends and planning to use both buses and subways, it is more convenient for each passenger to carry and use a separate transportation card.

4. Why Additional Fares May Be Charged During a Transfer

A Transfer Does Not Always Mean a Free Ride

A transfer discount does not make the entire journey free.

Instead, it prevents passengers from paying multiple full base fares and calculates the final amount according to the total distance traveled and the types of transportation used.

In the Seoul metropolitan area, the highest applicable base fare among the transportation modes used may apply. Additional distance-based charges may also be added after the basic travel distance is exceeded.

If you transfer to a more expensive service, such as certain express or metropolitan buses, you may also be charged the difference between the base fares.

Therefore, even if the card reader announces that a transfer has been applied, an additional amount may still be deducted for the following reasons.

The base fare of the next transportation service is higher.
The total travel distance exceeds the included distance.
The route or transportation service has a separate additional fare.

Common Reasons Transfer Discounts Fail

1. Failing to Tap Out on a Bus

If your bus exit is not recorded, your next ride may not be connected correctly to the previous trip.

2. Failing to Tap Out of the Subway

If you move your card too quickly or place several cards near the reader at the same time, the exit may not be recorded properly.

Always check the gate display and listen for the confirmation sound.

3. Exceeding the Transfer Time Limit

The transfer is based on the time you tap your card when boarding the next bus or entering the next subway station.

Even if you have been waiting at a bus stop, the discount may not apply if you tap your card after the time limit has expired.

4. Boarding the Same Bus Route Again

A bus traveling in the opposite direction may still be considered the same route if it has the same route number.

5. Using a Different Transportation Card

A physical card, mobile transportation card, and postpaid credit card may all be recognized as separate payment methods.

6. Insufficient Card Balance

Prepaid transportation cards must have enough remaining balance to cover the next ride.

Even during a transfer, boarding may be refused if the card does not have sufficient funds.

What to Do If You Forget to Tap Out

If you have already left the bus or subway, do not tap your card randomly on another reader.

Contact the transportation operator or transportation card customer service center and ask them to check your usage record.

Prepare the following information before contacting customer service.

Date and approximate time of travel
Boarding and exit stations or bus stops
Bus route number
Transportation card number
Amount charged

5. Regional Differences and Important Points to Check

Subway and bus transfer rules are not identical throughout Korea.

The Seoul metropolitan area operates an integrated transfer system covering Seoul, Gyeonggi Province, and Incheon. Other cities, including Busan, Daegu, Daejeon, and Gwangju, may have different transfer time limits, permitted numbers of transfers, and rules for boarding the same route again.

Busan also offers transfer discounts between city buses, village buses, and the subway. However, passengers must transfer within the permitted time and follow local limits on the number of transfers.

Discounts may not apply when boarding the same route again or re-entering the subway after leaving through an exit gate.

Before traveling to another city, check the following information.

The local bus information system or transportation authority website
Transfer time limit
Maximum number of transfers
Rules for boarding the same bus route again
Whether airport buses and intercity buses are included
Whether transfers between neighboring cities are supported
Accepted transportation card types

Airport limousine buses, express buses, intercity buses, and sightseeing buses often use separate fare systems and may not be included in local transfer discount programs.

Do not assume that every service called a “bus” qualifies for a transfer discount. Check the specific route information before boarding.

🔗 Check Busan Subway and Bus Transfer Rules

Subway and Bus Transfer Q&A

Q1. Can I still receive a transfer discount if I forget to tap out of a bus?

In most cases, you may not receive the correct transfer discount.

The bus exit tap records your travel distance and the starting time of the transfer period. If it is missing, the next subway or bus ride may be treated as a separate journey, or an additional fare may be charged.

Q2. Is it considered a transfer if I leave a subway station and enter the same station again?

A normal subway transfer must be completed inside the station without passing through a regular exit gate.

If you leave the paid area and re-enter the station, the trip may be treated as a new ride. Some stations operate special transfer or re-entry systems, so follow the station signs or ask station staff for assistance.

Q3. Why was an additional fare charged even though the transfer was accepted?

An additional amount may be charged if the total travel distance exceeds the included distance or if the next transportation service has a higher base fare.

A transfer discount reduces repeated base fares, but it does not make all connected rides completely free.

Conclusion

Using subway and bus transfers in Korea is simple once you remember a few basic rules.

Always tap your transportation card when boarding and getting off, and continue using the same card until your journey is complete. In the Seoul metropolitan area, passengers generally need to board the next transportation service within 30 minutes, while a longer time limit applies during late-night and early-morning hours.

Avoid boarding the same bus route again, and do not leave the subway through a regular exit gate when transferring between subway lines.

A transfer confirmation also does not always mean that no additional amount will be charged. Distance-based fares and fare differences between transportation services may still apply.

Finally, transfer systems vary by region. Before visiting another city, check the local transportation authority or bus information website for the applicable time limits, eligible routes, and accepted transportation cards.

행:Hang

Guide to Subway and Bus Transfers in Korea: Card Tapping, Time Limits, and Fare Discounts