Kids' Fares Don't Discount Automatically — Age Registration and Why Child/Youth Rules Differ by Transport

You can buy a child transit card and put it right in your kid's hand, and the adult fare will still be deducted until you register the age. On the Seoul metropolitan subway, that means 1,550 KRW gets charged instead of 550 KRW. The more painful part comes next. Article 19(4) of the AREX Passenger Transport Terms states that if you haven't registered, the adult fare applies, and "where the adult fare has been applied, the company shall not refund the difference." In other words, if you go months without realizing it and then catch on, there's no way to undo it.

Registration itself is surprisingly simple. The T-money non-member registration page asks for just three things: card number, CVC (the last three digits on the back of the card), and date of birth. No name, no resident registration number, no identity verification step. And Article 2 of the AREX terms, in defining "infant" and "child," specifically notes that each category "includes foreigners." Institutionally, foreign children were not left out.

The place where the math actually goes sideways is somewhere else. The boundaries for "child" and "youth" differ by mode of transport. A 15-year-old who pays 900 KRW on the subway pays the adult fare on the KTX. The KORAIL Passenger Transport Terms divide passengers into only three categories — infant, child, and adult — with no youth category at all. AREX has a youth fare on its All-Stop trains but not on the Express train.

Until You Register, Adult Fares Get Charged — and the Difference Never Comes Back

By T-money's standard, the child fare applies from age 6 through age 12, and the youth fare from age 13 through age 18. Even if the card says "child" right on it, if that date of birth isn't registered with the card issuer, the system simply calculates it as an adult.

There's also a deadline, and it matters. Discount registration must be done within 10 days of first use. There are three places to do it.

• T-money website — just enter the card number, CVC, and date of birth; no account signup needed.
• Convenience stores — GS25, CU, 7-Eleven, and emart24 can process it.
• Station customer service desks — available at Seoul metropolitan subway Lines 1–8 and Incheon Subway Lines 1–2.

Once a date of birth has been registered at a convenience store or station, that card keeps applying the discounted fare afterward without any separate discount registration.

Once registered, the fare also follows along automatically as your child's age changes. T-money gives the example that "for someone born on June 30, the general fare applies starting July 1, the day they turn 19." That said, this is just an illustrative example, so it's safer to confirm with the card issuer exactly when the fare changes around a birthday boundary. If you switch card types, the new fare applies starting 3 business days later.

For handling incidents other than registration — a lost card, or balances draining strangely — we've covered that separately in Transit Card Trouble and Balance Problems.

Foreign Children Are Covered Too — but Practice Varies by Counter

The terms are clear. Article 2, items 21 and 22 of the AREX Passenger Transport Terms define "infant" (under age 6) and "child" (age 6 to under 13, or elementary school student), and each definition includes the phrase "includes foreigners." This is not a clause that cuts by nationality.

The same goes for online registration. The T-money website registration form asks only for the card number, CVC, and date of birth — there's no field for nationality at all. It doesn't request an alien registration number or a passport number. There's no step requiring identity verification through a Korean mobile number, either. That makes the online route the smoothest path for foreign families.

The issue is offline. How convenience stores and station customer service desks actually handle a foreign child's card, and whether they ask for documents like a passport, is not confirmed in official guidance. Answers may vary by staff member, so if you're planning to register offline, we recommend calling the T-money customer center at 1644-0088 first.

The Thresholds Differ by Mode — Subway / Rail / AREX Compared

A single child riding the subway and the KTX on the same day can change status twice. Here's the comparison table.

The second row is the key one. Article 2, item 1 of the KORAIL Passenger Transport Terms divides passengers into only infant, child, and adult. Rail has no youth fare, so the adult fare applies from the 13th birthday. If you take the KTX from Seoul to Busan with a middle schooler who has already turned 13, your child needs an adult ticket. Conversely, a 7th grader whose birthday hasn't come yet is still 12, and still qualifies for the child fare. The standard is age in years, not school grade.

Here's how the fare figures break down.

The subway base fare took effect on June 28, 2025, and Seoul city bus fares took effect on August 12, 2023. The distance-based surcharge kicks in beyond the 10 km base distance — every 5 km up to 50 km, then every 8 km beyond 50 km.

Look at the second row again. Single-journey transit cards have no youth discount whatsoever. It's 1,650 KRW, exactly the same as an adult. Children, on the other hand, pay 550 KRW even on a single-journey ticket, the same as with a transit card. So if a short-stay family who hasn't gotten cards yet buys single-journey tickets every time, an elementary-school-aged child gets the full discount while a middle or high schooler gets zero. If you have a teenager, buying a rechargeable transit card and registering the age is clearly the better deal. If this is your first time using the Seoul metropolitan subway at all, read it alongside our Complete Seoul Subway Guide.

Village buses, circular buses, and late-night buses (N) also have age-based fare tiers. However, since we only had one source for these, we won't list the amounts here. Please check the fares for your specific route in T-money's public transport guidance.

How Many Infants Ride Free — 1 on KTX, 3 on the AREX All-Stop Train

This is the calculation families with multiple kids get wrong most often. The number of free infants differs by mode.

Article 7(2) of the KORAIL Passenger Transport Terms provides that one infant without an assigned seat rides free per guardian aged 13 or older, and beyond one infant, the separately set infant fare applies. So if one parent boards with two infants, the second one incurs an infant fare. With two parents, one infant is covered per parent.

The AREX All-Stop train is far more generous. Article 12(7) of its terms provides that when a single guardian accompanies more than 3 infants, the child fare applies starting from the excess infants. Read in reverse, that means up to 3 infants ride free per guardian.

Even within AREX, the Express train is different again. Article 33(2) says an infant is treated as a child in three cases: ① group travel, ② the portion exceeding one infant when a single guardian accompanies more than one, and ③ when a seat is assigned to the infant. In effect, the Express train allows one free infant per guardian. For problems that stop you at boarding rather than at the fare — like pushing a stroller on board — see Riding Korean Public Transport with a Stroller, organized by statute and terms of carriage.

SR (SRT) has guided that children aged 6 to under 13 get a 50% fare discount, infants under 6 ride free at one per guardian (no assigned seat), and infants with an assigned seat get a 75% discount. However, with the KORAIL–SR integration on September 1, 2026, SRT was folded into KTX-Sancheon and booking was unified into the single "KORAIL+" app. Whether these discount rates carried over intact under KORAIL's standards after integration is not yet confirmed by official guidance, so please go by the amount shown on the booking screen. For everything that changed with the merger, see our separate Complete Guide to the KTX–SRT Integration. We also couldn't confirm KTX's child discount rate or the accompanying-infant seat-assignment discount rate on KORAIL's primary pages, since KORAIL's terms delegate those to website postings.

The Moment You're Asked for ID — Foreign Kids Without a Youth ID Card

This is a wall that comes up only for foreign families. Article 22(2) of the AREX terms lists the tickets for which you must present identification when staff request it: youth cards (a youth ID card, student ID, or other document confirming age) and preferential-use cards. And Article 23(1), item 6 provides that if you cannot present such documentation, the ticket is void.

What's worth noting is that child cards are not on the presentation list. Children in elementary school or younger will essentially never be asked for ID; the ones who hit the wall are kids aged 13 to 18. A child who doesn't attend school in Korea has no Korean student ID, and usually no youth ID card either.

Here's how the youth ID card works. It's an identification card issued to youths aged 9 through 18 regardless of student status, under Article 4 of the Youth Welfare Support Act. You apply at a eup/myeon/dong community service center, in person or through a proxy; issuance is free; a transit card function can be added; and it's valid until the day before you turn 19.

But we can't tell you whether foreign children can obtain a youth ID card. Neither Government24 nor the Ministry of Gender Equality and Family guidance states any nationality requirement. Since it says neither yes nor no, you'd need to ask the Ministry of Gender Equality and Family directly at 02-2100-6242, or your local community service center.

Express buses have stricter conditions. The integrated express bus booking guidance states that the youth (middle/high school student) discount on standard express buses applies only if you present a student ID or youth ID card at the terminal in person, and you must carry it while riding as well. If you book a discounted ticket online and show up at the terminal without documentation, the discount is voided, and if it's deemed fraudulent use, a charge of 10 times the fare applies. If your child has no documentation, it's safer to just book an adult ticket from the start.

What Misuse Costs You — 10x and 30x, and When It Can Be Reversed

Surcharges run as high as a criminal fine, so you really need to know these.

Article 12(1) of KORAIL's terms breaks the multiplier down by reason: no ticket, 1x; evading or refusing ticket inspection, 2x; an ineligible person using a discounted ticket or product with eligibility restrictions, 10x; fraudulent use of a group ticket, 10x; being caught a second time, 10x; and forging or altering a ticket, 30x. These standards have been in effect since October 1, 2025 (Supplementary Provisions Art. 2).

There's a remedy procedure here you should definitely know about. Article 12(3) of KORAIL's terms provides that someone who paid a surcharge because they couldn't present a fare-discount ID or certificate may, within one year of the travel date, submit ① the ticket in question, ② an ID or certificate confirming they qualified for the fare discount, and ③ the surcharge receipt to a station and request a refund (excluding unstaffed stations and sales agencies; a minimum fee is deducted). If you were actually eligible and simply didn't have the document that day, don't just eat the cost.

AREX has a similar caveat. Articles 26(1) and 46 state that if you notify staff in advance that you were unable to buy a ticket or lost it for unavoidable reasons, and the reason is accepted, no surcharge will be imposed. Speaking up before you pass the fare gate and explaining after you've been caught produce completely different outcomes.

K-Pass Doesn't Cover Kids — Gyeonggi's Refund Is Essentially the Only Route

You'll hear plenty of advice in foreigner communities to "get your transit costs refunded." But none of it applies to children. The refund program Modu's Card (formerly K-Pass) is open to those aged 19 and over, so children and youths aged 6 to 18 aren't eligible to apply at all. If you search, K-Pass and Modu's Card show up separately, but they're not two different programs — they're the old and new names of the same initiative, so there's nothing extra to look into for your child.

The Climate Card is an entirely different animal. It's not a refund program but a flat-rate pass operated by the Seoul city government, and there's no dedicated child or youth tier. So for your child you'd have to buy the adult tier anyway, and since the child fare is only 550 KRW, kids rarely ride enough to make a flat-rate pass worthwhile (please confirm with Seoul's official guidance whether children can buy one and whether age limits apply). Refund programs for adults are covered separately in our K-Pass (Modu's Card) Guide for Foreigners.

The one route left open for kids is Gyeonggi Province. The Gyeonggi Children and Youth Transit Cost Support platform describes eligibility this way — "ages 6 to 18 with resident registration in Gyeonggi Province (including foreign children and youths residing in the province, and overseas Korean nationals with a reported domestic residence)." It's one of the few programs that explicitly includes foreigners.

Here are the conditions.

• The support cap is 60,000 KRW per quarter / 240,000 KRW per year, paid out in local currency (regional gift certificates).
• Eligible modes are (wide-area) buses, subway (light rail), GTX, Sinbundang Line, and shared bikes (Ddokta).
• Airport buses, intercity buses, taxis, and trains are excluded.
• Applying requires a simple/joint/financial certificate in the name of the child/youth or a proxy, transit card registration (up to 2 cards), and local currency registration.
• You can sign up any time of year; inquiries go to 1577-8459 (weekdays 9 a.m.–6 p.m.).

The barrier isn't eligibility — it's procedure. Eligibility is explicitly open, but the application stage requires a digital certificate and local currency. A foreign family that hasn't been able to obtain a certificate yet may get stuck right here. We weren't able to confirm whether foreign children and guardians can actually pass residency verification with a certificate, or whether local currency accounts can be opened in a foreigner's name, so calling 1577-8459 first will save you time.

Choosing Your Child's Category When Booking KTX, Express Buses, or AREX

Whether you enter your child as a "child" or an "adult" on the booking screen varies by mode. Use these standards.

Let's also spell out the AREX All-Stop train fare structure. Under Articles 12(2) and 12(3) of the terms, children pay a base fare of 550 KRW with a 50% discount on the adult distance surcharge, while youths pay a 900 KRW base fare with a 20% discount on the surcharge. The discount is structured to be much deeper for children.

We won't list current Express train prices in this article. The list prices in Appendix 2 of the AREX terms are 18,100 KRW and 18,700 KRW for adults from Seoul Station to Incheon Airport Terminal 1 and Terminal 2 respectively, and 9,500 KRW for children on both sections — but Article 34(4) provides that the company may implement and post discounts as a matter of business policy. In other words, the actual sale price may differ from these list prices, so check the booking screen.

When you're traveling with kids, the most annoying part is that booking counters are scattered across modes. LACHA is a transportation and payment super-app for foreigners that you can use right away with no identity verification, handling KTX, express buses, AREX, taxis, and transit cards all in one place. You can get started with just your passport — no Korean bank account or phone number needed — and pay with overseas mobile payment services like Alipay and WeChat Pay, or with international cards. That said, please check in the app how child tickets and accompanying-infant selection appear on screen — the age standards themselves differ by mode, as we saw above. If you're curious about train seat classes and refund rules, read KTX Seat Classes and Refunds as well.

Want to search and book KTX and express buses in one app? Check out LACHA.

Built to work without a Korean phone number or bank account, with overseas payment methods like Alipay, WeChat Pay, and Apple Pay. Taxi hailing plus KTX, express bus, and airport railroad (AREX) booking — all in one app.

Enter code GUIDE3 at sign-up for 3,000P instantly

Download now

Frequently Asked Questions (FAQ)

Q1. I bought a child card but the adult fare was charged. Can I get the past fares back? Unfortunately, that's difficult. Article 19(4) of the AREX Passenger Transport Terms specifies that if the age isn't registered, the adult fare applies, and where the adult fare has been applied, the company does not refund the difference. What you can do now is stop the bleeding going forward. Register right away on the T-money website with the card number, CVC, and date of birth. The registration deadline is technically within 10 days of first use, but even if that's passed, it's worth calling the T-money customer center at 1644-0088 to check whether a convenience store or station customer service desk can process it.

Q2. Can foreign children register their age too? Institutionally, yes, they're covered. Article 2 of the AREX terms notes that the definitions of "infant" and "child" each "include foreigners," and the T-money online registration form doesn't ask about nationality — it takes only the card number, CVC, and date of birth. There's no field requiring an alien registration number or passport number, either. That said, how convenience stores and station counters actually handle registration for foreign children isn't confirmed in official guidance, so if you plan to go offline, call 1644-0088 first.

Q3. My child is 15 — does the youth fare apply on the KTX too? No. Article 2, item 1 of the KORAIL Passenger Transport Terms divides passengers only into infant (under 6), child (6 to under 13), and adult (13 and over). Rail has no youth fare category, so the adult fare applies from age 13. That same child gets the 900 KRW youth fare on the Seoul metropolitan subway and 900 KRW by card on Seoul's main and branch buses, but needs an adult ticket on the KTX. AREX likewise has a youth fare (900 KRW base) on All-Stop trains but no youth category on the Express train.

Q4. What if my child has neither a youth ID card nor a student ID? Article 22(2) of the AREX terms requires youth card users to present documentation confirming their age when staff ask, and Article 23(1), item 6 provides that failure to present it voids the ticket. The express bus middle/high school student discount likewise requires on-site presentation at the terminal. Youth ID cards are issued free to those aged 9 to 18 regardless of student status, under Article 4 of the Youth Welfare Support Act — but whether foreign children can obtain one can't be stated definitively, since neither Government24 nor Ministry of Gender Equality and Family guidance lists a nationality requirement. Check with the Ministry of Gender Equality and Family at 02-2100-6242 or your local community service center.

Q5. Can my child get a K-Pass refund? Modu's Card (formerly K-Pass) is open to those aged 19 and over, so children and youths aged 6 to 18 can't apply. K-Pass and Modu's Card aren't separate programs — they're the old and new names of the same initiative, so there's no need to research them separately. The Climate Card isn't a refund program but a flat-rate pass, and it has no dedicated child or youth tier, so you'd have to buy the adult tier for your child, which rarely pays off (please confirm with Seoul's official guidance whether children can buy one and whether age limits apply). The one route open for kids is Gyeonggi Province's Children and Youth Transit Cost Support. Eligibility explicitly extends to "foreigners residing in the province and overseas Korean nationals with a reported domestic residence," and it refunds 60,000 KRW per quarter / 240,000 KRW per year in local currency. That said, it's limited to Gyeonggi residents and the application requires a digital certificate and local currency registration. Inquiries: 1577-8459 (weekdays 9 a.m.–6 p.m.).