Best eSIM for Seoul (2026): Which Network You Actually Get, and What It Costs
For the two-week traveller doing Seoul plus a KTX run to Busan. Which carrier the eSIM lands on, what the regulator's own tests say about it, and the price per gigabyte.
Quick answer: For the independent traveller spending two weeks in Seoul with a KTX trip out of the city. The Korea country plan roams on LG U+ on 4G and 5G.
Key takeaways
- Carrier and networks: the Korea country plan roams on LG U+ (4G and 5G). The alternative is a South-Eastern Asia regional plan covering 18 countries on SKTelecom 5G, which costs more for Korea alone.
- Dated prices (23 September 2026): 5 GB for 30 days US$10.12 (US$0.34 a day, US$2.02 per GB), 10 GB for 15 days US$18.67 (US$1.24 a day, US$1.87 per GB), 20 GB for 15 days US$29.27 (US$1.95 a day, US$1.46 per GB), unlimited for 15 days US$49.61 (US$3.31 a day).
- The honest network picture: in the 2025 MSIT and NIA quality assessment, as reported by Korean trade press, LG U+ posted the lowest 5G and LTE download speeds of the three carriers, and also the fewest zones rated inadequate, including only 3 weak subway sections against 6 each for SKT and KT.
- After the bucket, fixed plans drop to 128 kbps. Good enough for KakaoTalk, email and map tiles. Not enough for a video call.
The traveller this is written for has two weeks, a base in Seoul, and one long train ride in the plan. What they say out loud on day one is usually this: "Google Maps will not give me walking directions here, so I am on Naver Map every ten minutes, and I do not want to be the person with no signal on the KTX."
Does a Seoul eSIM roam on LG U+, and what does that mean underground?
LG U+, on 4G and 5G. That is the carrier behind the Korea country plan, and it matters more than the brand on the checkout page. The other option in the catalogue is the South-Eastern Asia regional plan, which includes Korea and 17 other countries but roams on SKTelecom (5G) and costs noticeably more for the same data. If Korea is your only destination, the country plan is the one to read.
| What you are doing | Bandwidth it needs | Does it survive at 128 kbps? |
|---|---|---|
| KakaoTalk messages, email, Naver Map tiles | Under 0.5 Mbps | Yes, slowly |
| Zoom audio-only call | 60 to 80 kbps | Yes |
| Zoom 1:1 video call, 720p | 1.2 Mbps up and down | No |
| Zoom group video call, 1080p | 3.8 Mbps up, 3.0 Mbps down | No |
| YouTube live at 720p, 30 fps | 4 Mbps recommended | No |
What does a Seoul eSIM cost per day and per gigabyte?
| Plan | Total | Per day | Per GB |
|---|---|---|---|
| 3 GB, 7 days (LG U+) | US$9.10 | US$1.30 | US$3.03 |
| 5 GB, 7 days (LG U+) | US$10.11 | US$1.44 | US$2.02 |
| 5 GB, 30 days (LG U+) | US$10.12 | US$0.34 | US$2.02 |
| 10 GB, 15 days (LG U+) | US$18.67 | US$1.24 | US$1.87 |
| 20 GB, 15 days (LG U+) | US$29.27 | US$1.95 | US$1.46 |
| 50 GB, 30 days (LG U+) | US$49.55 | US$1.65 | US$0.99 |
| Unlimited, 15 days (LG U+) | US$49.61 | US$3.31 | not applicable |
| 10 GB, 15 days, 18 countries (SKTelecom) | US$24.55 | US$1.64 | US$2.46 |
Is LG U+ good enough in Seoul, honestly?
- Seoul and the other big cities are the best-served part of Korea. Average 5G download in large cities was about 1,090 Mbps in the 2025 assessment as reported by Korean trade press.
- Rural Korea is materially slower, averaging about 617 Mbps, roughly 57% of the big-city figure.
- The remaining bad spots cluster underground and on the rails. Of 600 assessed areas, the 32 still rated inadequate for 5G were concentrated in subway and high-speed rail sections, with several KTX stretches unimproved year on year.
- Do not believe the line that every metre of the Seoul subway is fully covered. The regulator's own assessment says otherwise, which is exactly why the carrier with the fewest weak sections is a reasonable one to be roaming on.
How much data does two weeks in Seoul really use?
| A day in Seoul | Rough data |
|---|---|
| Naver Map or KakaoMap, checked constantly, plus transit directions | 0.2 to 0.35 GB |
| KakaoTalk, email, photos sent home | 0.2 to 0.3 GB |
| Translation, menus, web browsing, some social | 0.3 to 0.5 GB |
| One hour of 720p video calls, one to one | About 1.1 GB |
| Typical sightseeing day, no video calls | About 0.8 to 1.1 GB |
| Day with an hour of video calls home | About 1.9 to 2.2 GB |
Should I just buy a SIM at Incheon Airport instead?
| Local SIM at Incheon | Travel eSIM | |
|---|---|---|
| Korean phone number | Yes | No, data only |
| Paperwork | Passport, registration at the counter | None on arrival |
| When you are online | After you find the desk and queue | Walking off the plane |
| Price | Not verifiable from an official page, ask at the counter | Published at checkout, see the table above |
| Useful for Korean identity verification | No, per the retailer's own notice | No |
So take the local SIM if you specifically need a Korean number for restaurant bookings or a delivery courier to call you. Take the eSIM if what you need is data from the moment you land.
Terms and conditions
- Information only. This article is information about mobile data options for travellers in South Korea. It is not an offer or sale of any product or service, and it is not financial, legal or tax advice.
- For readers in the United States. This article provides information only. It is not an offer, solicitation or sale of any product or service, and it is not financial, investment, legal or tax advice. Fizen is not offered to US Persons.
- Independent. Fizen is not affiliated with, endorsed by or a partner of LG U+, SK Telecom, KT, Incheon International Airport, Naver, Kakao or the Korea Tourism Organization. Network measurements quoted are from the 2025 MSIT and NIA assessment as reported by Korean trade press, and they change each year.
- Rules change, so check before you travel. Entry requirements, K-ETA rules and SIM registration rules are set by the Korean authorities and change. Apply for K-ETA only at the official portal and check the official sources before you rely on anything here.
- Data only. A travel eSIM carries data. It does not give you a local phone number and it does not send or receive SMS, so keep your home SIM active for bank one-time codes and calls.
- eSIM terms. Prices, validity, data size, throttle speed and hotspot rules are the ones shown at checkout. Real speed depends on the network and where you are. Your phone must support eSIM and be carrier-unlocked. Most travel eSIMs cannot be topped up, so more data means a new eSIM.
- Full terms. Master Terms of Use, Privacy Policy and Disclaimer on the Fizen site.
Sources
- Incheon International Airport: facility directory, Terminal 1 roaming centres
- Korea Tourism Organization: mobile connectivity for visitors
- MSIT and NIA: 2025 communications coverage and quality assessment (published 30 December 2025)
- Korean trade press report of the 2025 quality assessment figures
- Seoul Metropolitan Government: free public Wi-Fi Kkachi On
- Act on the Establishment and Management of Spatial Data, Article 16 (Korea Law Translation Center, Korea Legislation Research Institute)
- JURIST: South Korea conditionally approves Google high-precision map data export (February 2026)
- Kakao Help: KakaoTalk sign-up with an international number
Updated 23 September 2026.
