2026 · 7 providers · 85 plans · 3 networks · 1 that names its network
Best eSIM for South Korea
Picked by your trip, not by hype. Korea is the country where the carriers sell you an eSIM themselves, where "unlimited" means five different things, and where the phone-number wall that every 2025 guide warns about started coming down this summer.
Do you need an eSIM in South Korea? six honest cases
AT&T and Verizon day passes run $10 to $12 a day. A ten-day Korea trip on a day pass costs more than any plan on this page, and Korea is a country where you will be on the phone constantly: Naver Map does not work offline the way Google Maps does. Airalo's 10GB at $19.00 ends that arithmetic on the AREX train from Incheon.
Korea runs on its own apps. Naver Map for walking and transit, Kakao T for taxis, Papago for menus, KakaoTalk for the guesthouse owner. All of them want a live connection at the moment you are standing on the wrong exit of a station with fourteen exits. Offline maps do not know which exit has the escalator.
Some T-Mobile plans include Korea data at throttled speed, and Fi includes it at full speed with a daily budget. Enough for KakaoTalk and maps, not enough for Naver Map redrawing a subway transfer while you walk. Land, test it, keep GigSky's free 100MB installed as the fallback.
Every travel eSIM here is data-only. Fewer Korean apps demand a local number than they did a year ago, but Coupang still does, and some restaurant kiosks still do. If that is you, LG U+, KT and SK Telecom sell tourist eSIMs with a real 010 number, at the cost of a passport registration after you land.
Every travel-eSIM "unlimited" on this page is a daily cap: 5GB, 3.5GB, 3GB, 2GB, or a cap nobody will print. LG U+ sells a tourist eSIM it calls "no speed cap, truly unlimited" for about $20 over five days, and SK Telecom's partner sells seven uncapped days for $20.70. We priced it all side by side, and we earn nothing on the winners.
Jeju airport has had no carrier counters since the end of June 2026. SK Telecom closed its roaming center there; KT closed in 2018. Every guide that still says "grab a SIM when you land in Jeju" is describing 2025. Install an eSIM before you fly, or buy at Incheon or Gimhae on the way through.
Your trip three taps, one answer
Answer three questions and we name the plan, with the reason written out. Already know what you want? Jump to the picks.
How long are you going for?
How will you use it? Pick everything that applies.
Where are you going?
The picks in short
Airalo
Best for most trips, and the only linkable eSIM that names its network $19.00 10GB / 30 days- Shows SK Telecom as its primary network on its own Korea page. SKT is Opensignal's Best Network in Korea for December 2025, with the top coverage score of the three carriers
- 5GB for $10.00 over 7 days is the cheapest 5GB on this site, linked or not, and the plans carry 5G
- 50GB for $49.00 over 30 days is a dollar a gigabyte with no daily cap, the best heavy-use bucket we can link
Watch out: It is $1.21 more than GigSky at 10GB, its unlimited caps at 3GB a day, and Airalo's own website shows Canadian dollars from some connections, so check the currency before you compare.
Trustpilot 4.1/5 · 42,273 reviews
See Airalo's Korea plansGigSky
Cheapest at 1GB, 3GB and 10GB, with a free trial $17.79 10GB / 30 days- Cheapest 10GB we can link at $17.79, cheapest 1GB at $2.99 and cheapest 3GB at $8.49 over a full fifteen days
- Free 100MB for 7 days, no card, so you land connected whatever else goes wrong. That matters more now that Jeju airport has no counters
- Sells its daily plan honestly: 3.5GB a day is in the plan name, not hidden behind the word unlimited
Watch out: GigSky publishes nothing about which Korean network it rides, it sells nothing above 10GB, and it pays us the highest commission of the four brands here (20%). Read the reasoning and decide.
Trustpilot 4.3/5 · 6,288 reviews
See GigSky's Korea plansSaily
Best trust record, and the one to hotspot from $34.99 Unlimited / 10 days- Trustpilot 4.7 from 30,662 reviews, the best record on this page by a distance
- Unlimited with a published 5GB per day cap, the largest daily allowance any brand we link sells for Korea
- Hotspot allowed on every plan, and 20GB for $29.99 over 30 days if you would rather have a bucket
Watch out: Saily publishes nothing about its Korean network, and its Korea page would not load for us on the day we checked, so every Saily price here comes from esimdb rather than from Saily.
Trustpilot 4.7/5 · 30,662 reviews
See Saily's Korea plansYesim is the fourth brand we can link and it owns the top of the table: the cheapest 20GB at $27.96 and the only 30GB, at $35.04, plus 1GB for a whole month at $3.00. It publishes no daily cap on its unlimited plan, and Trustpilot suspended its score during a fake-review cleanup in 2026 before restoring it, 4.3 across 2,943 reviews as of September 7, 2026. We say the history rather than pretending it did not happen. The full Yesim review explains when the saving is worth it. And Ubigi, which we cannot link, sells 10GB for $14.00 on SK Telecom and LG U+ and is in every table below anyway.
Compare every South Korea eSIM side by side
| Provider | Best for | Price anchor | Korean network | Unlimited cap |
|---|---|---|---|---|
| Airalo | Most trips; the only linkable brand that names its network | $19.00 / 10GB | SK Telecom (shown on its page) | 3GB/day, then 1 Mbps |
| GigSky | Cheapest 1, 3 and 10GB; free 100MB trial | $17.79 / 10GB | not published | no unlimited; 3.5GB/day packs |
| Saily | Best support record, hotspot, unlimited | $18.99 / 10GB | not published | 5GB/day, then throttled |
| Yesim ¹ | Cheapest 20GB and the only 30GB | $19.20 / 10GB | not published | no cap published |
| Ubigi | Cheapest 10GB anywhere, two networks published | $14.00 / 10GB | SK Telecom + LG U+ (published) | 7 days $25: 25GB total, then 2 Mbps |
| Holafly ¹ | Unlimited only; hotspot capped at 1GB/day | $36.50 / 10 days unl. | SK Telecom + LG U+ (published) | no cap published |
| Nomad | Big buckets: 50GB for $39 | $18.00 / 10GB | SKT, KT or LG U+ (plan-dependent) | 2GB/day, then 512 kbps |
Prices in USD, checked September 7, 2026, before any promo code. Ubigi, Holafly and Nomad are listed unlinked because we earn nothing from any of them; Ubigi in particular is cheaper than every brand we link at 10GB and names two networks, and leaving it out would make this table a lie. ¹ Hover the marker for the Yesim and Holafly notes. The Korean carriers' own tourist eSIMs are not in this table because they are a different product with a phone number and no cap; they have their own page.
The cheapest South Korea eSIM at each size one row, one winner
| You need | Cheapest | Price | Runner-up |
|---|---|---|---|
| 1GB | GigSky | $2.99 / 7 days | Yesim $3.00 / 30 days, a month for one cent more |
| 3GB | GigSky | $8.49 / 15 days | Saily $8.99 / 30 days; Ubigi $7.00 / 7 days, unlinked |
| 5GB | Airalo | $10.00 / 7 days | GigSky $10.29 / 30 days |
| 10GB | GigSky | $17.79 / 30 days | Saily $18.99; Ubigi $14.00 / 30 days, unlinked |
| 20GB | Yesim | $27.96 / 30 days | Airalo $29.00 / 15 days; Ubigi 25GB $25.00, unlinked |
| 30GB+ | Yesim | 30GB $35.04 / 30 days | Airalo 50GB $49.00 / 30 days; Nomad 50GB $39.00, unlinked |
Read the validity column, not just the price. GigSky's 1GB is one cent cheaper than Yesim's and expires twenty-three days sooner. Airalo wins 5GB on a 7-day plan; for a longer trip GigSky's 5GB at $10.29 over 30 days is the one you want for 29 cents more. Ubigi undercuts three of these rows and cannot be linked here. Checked September 7, 2026.
Two ways to act on that table. Take Airalo and know you are on SK Telecom with 5G, or take GigSky and save $1.21 at 10GB without knowing which network you get. In Seoul and Busan that dollar is the whole difference; outside them, it is not.
See Airalo plans See GigSky plans Work out your size firstWho each provider is actually for plain answers
You want to know which network you are on, you are leaving the cities at any point, or you want the cheapest 5GB. Also the best big bucket we can link: 50GB for $49 with no daily cap. Pays us the least of the four.
Full review →You are staying in Seoul and Busan, where all three networks are excellent and the cheapest 10GB wins. Install the free 100MB before you fly regardless; it costs nothing and it is the only free trial here. Pays us the most of the four, and we say so.
Full review →You are hotspotting a laptop, streaming on the KTX, or the support record matters to you. The 4.7 from 30,662 reviews is earned, and the 5GB daily cap is the largest any brand we link publishes for Korea.
Full review →You want 20GB or 30GB, which Yesim sells cheaper than anyone we link, and you have read the Trustpilot history and decided it does not change your mind.
Full review →You want the cheapest 10GB in Korea on two named networks and do not care that we earn nothing from it. $14.00 for 10GB, $25.00 for 25GB, and a 7-day unlimited with the total printed on the page.
Full review →Which Korean network your eSIM rides, and why only one brand will tell you SKT, KT or LG U+
Korea has three networks and all three are superb. This is the one country we cover where the carrier behind your eSIM matters less than the price, with two exceptions: the high-speed trains, and the deep valleys. Even so, only one brand we can link will tell you which network you are buying.
SK Telecom
The one that wins the measurementsOpensignal's Best Network in Korea for December 2025, with the top coverage score (9.4 out of 10 against KT's 9.1 and LG U+'s 8.6) and the fastest 5G. About 39% of Korean lines are on it. Among the brands we link, only Airalo shows it as its network. Ubigi and Holafly publish it too, and we earn nothing from either. Its reputation for holding up in the mountains is exactly that, a reputation, and we say so.
KT
Second on coverage, first on the seaA close second in every score, the only Korean operator running nationwide standalone 5G, and the network with maritime LTE reaching about 100 km offshore from island base stations, which is why the Ulleungdo ferry has a signal. No brand we can link publishes a KT agreement. Nomad, unlinked, says its plans ride SKT or KT depending on the plan.
LG U+
Excellent in cities, no 3G to fall back onWins Opensignal's 5G availability score at 90.3% and is faultless in Seoul and Busan. Its coverage score trails the other two, and it never built a 3G network, so where LTE thins out in a deep valley the phone shows no service rather than a slow bar. Ubigi and Holafly publish it as their second network. Airalo appears to have moved off it: a July-2026 traveler review reported Airalo on LG U+ in 2025, and Airalo's page now shows SK Telecom.
Saily, GigSky and Yesim publish nothing about their Korean network, and every table on this site says not published for them rather than repeating a blog's guess. The practical rule: a Seoul, Busan and KTX itinerary works on any of these, and the eSIM choice comes down to price. Add Seoraksan, the Jirisan ridge, the Jeju interior or a ferry and knowing the network stops being a detail. The full network page has the government's 2025 measurements, the KTX problem and the 2025 hacks.
If your route leaves the cities, this is the decision: Airalo is the only eSIM we can link that tells you its network, that network is SK Telecom, and it costs $1.21 more than the cheapest 10GB on the page.
See Airalo Korea plans Read the network breakdownSources & freshness: Network claims taken from each brand's own Korea page on September 7, 2026: Airalo shows "SK" as its primary network; Ubigi and Holafly list SK Telecom and LG U+; Nomad lists all three and says 5G only on its SKT plans; Saily, GigSky and Yesim publish nothing. Carrier scores from Opensignal's South Korea Mobile Network Experience report, December 2025, and the Korean Ministry of Science and ICT's 2025 quality evaluation released 30 December 2025. Market shares from Korean industry reporting for the first quarter of 2026.
What "unlimited" really means in South Korea the caps in one table
| "Unlimited" plan | Real daily high-speed cap | After the cap |
|---|---|---|
| Saily Unlimited (10 days, $34.99) | 5GB/day | The largest published daily allowance any brand we link sells for Korea, about $3.50 a day. Saily's fair-use post says it slows to 1 Mbps or less; esimdb lists 1 kbps; Saily's own Korea page would not load for us, so the throttle speed is unverified. |
| GigSky 3.5GB/day (7 days, $27.99) | 3.5GB/day | Not sold as unlimited at all, which is the honest version of the same product. The cap is in the plan name. GigSky does not print the speed after the cap on its Korea page. |
| Airalo Jjang Unlimited (10 days, $35.00) | 3GB/day | Drops to 1 Mbps for the rest of the day and resets at midnight, on SK Telecom. Airalo's Asialink regional unlimited is $26 for 7 days against $29 for the Korea-only one, and covers Japan too. |
| Yesim Unlimited (10 days, $34.77) | none published | Yesim says speed "may be limited in accordance with the network operator's Fair Usage Policy" and never gives the number. Trustpilot reviewers describe a 5 Mbps ceiling, which is a customer report, not a term. |
| Ubigi Unlimited (7 days, $25.00) · unlinked | 25GB total, then 2 Mbps | A total allowance rather than a daily one, printed on Ubigi's own plan page, on SK Telecom and LG U+. Spread evenly that is 3.6GB a day, and it is the cheapest travel-eSIM unlimited on this page. We earn nothing on it. |
| Holafly Unlimited (10 days, $36.50) · unlinked | none published | Holafly says its fair usage policy is "temporarily applied for no more than one day" and gives no gigabyte figure. Hotspot is limited to 1GB a day, the one number it does print. Its Trustpilot profile was under review on September 7, 2026. |
| LG U+ tourist eSIM (5 days, ₩27,500 ≈ $20) · carrier, unlinked | none, "no speed cap" | The carrier's own product, sold at lguplus.com, described as "No Speed Cap, Truly Unlimited", with a 010 number included. About $4 a day. The catch is a passport check at the airport counter for the voice version. SK Telecom's partner sells seven uncapped days for $20.70 on the same terms. |
Every travel-eSIM "unlimited" plan sold for Korea is a daily allowance with a different name, and the Korean carriers sell the genuinely uncapped version for less. Under about 1.5GB a day, a fixed 20GB pack at $27.96 is cheaper than any of them for a two-week trip. Figures from each brand's own published terms on September 7, 2026, not from a test. The full unlimited page works out the price per day and the cap in hours of video.
If you want unlimited from a brand we link, buy the largest published cap rather than the cheapest sticker: Saily prints 5GB a day, Airalo prints 3GB and 1 Mbps, and two brands here print nothing. If you want genuinely uncapped data, the carriers win and we earn nothing.
See Saily Unlimited Or read about the carrier eSIMsDo you still need a Korean phone number in 2026? less than every guide says
So the honest 2026 answer is: most visitors do not need a 010 number, and a data-only travel eSIM plus your home number left on for texts covers almost everything. Where it does not, the Korean carriers sell tourist eSIMs with a real 010 number, and the price of that number went up this year in paperwork rather than in won. Since December 2025 a passport can hold one prepaid line. LG U+ wants to see the passport at an airport counter before the voice version works; SK Telecom's partner wants it registered online after landing, between 08:00 and 22:00 Korean time. Face authentication at activation is being phased in from July 2026, with foreign IDs scheduled for the second half of the year.
A travel eSIM has none of that. Nothing is scanned, nothing is registered, and the profile is on your phone before the plane boards. The phone-number page lists exactly which apps still want a 010 number and the three ways to get one, and the carrier page prices LG U+, KT and SK Telecom's tourist eSIMs against the plans above.
How much data a South Korea trip actually uses real numbers
| Trip style | 5 days | 10 days | 14 days | 30 days |
|---|---|---|---|---|
| Naver Map, KakaoTalk, Kakao T, Papago | 1.5GB | 2.5GB | 3.5GB | 7GB |
| Plus photos, stories, some video | 4GB | 8GB | 11GB | 22GB |
| Plus laptop hotspot and calls | 9GB | 18GB | 25GB | 50GB |
| Sizes that fit | Airalo 5GB | GigSky 10GB | Yesim 20GB | Airalo 50GB |
Assumes hotel wifi most nights and no video streaming over cellular. Korea pushes the top row up rather than down: Naver Map re-downloads its tiles far more than Google Maps does, Papago's camera mode is how you read a menu and it runs at about 20 to 30MB an hour, and a 5G phone will happily pull a 1080p reel you did not ask for. Seoul's free public wifi is real and usable on the subway and in most cafes, which is why the numbers are not higher. Per-app figures are published estimates, not our measurements. The full calculator breaks it down per app and per persona.
Where a travel eSIM works and where the network choice starts to matter place by place
Nobody can promise you a bar of signal at a specific guesthouse. What we can do is name the carrier each place leans on and say what the government's own 2025 measurements found, so you know when any eSIM on this page is enough and when the network becomes the question.
| Where you are going | Network to prefer | What to expect |
|---|---|---|
| The cities, where most trips happen | ||
| Seoul and the subway | Any | Full 5G on all three carriers on every line and platform; the official 2025 evaluation measured 929 Mbps average 5G underground. Every plan on this page is fine here and the choice comes down to price. |
| Busan, Daegu, Gwangju, Daejeon | Any | The big cities averaged nearly 1.1 Gbps on 5G in the government test. The one soft spot in Busan is the Gamcheon Culture Village alleys, where everyone loses a bar or two between the houses regardless of carrier. |
| Incheon airport and the AREX | Any | Both terminals and the express train are covered end to end. The carrier counters in T1 Hall F and T2 near Gate A are open 24 hours if you want a local eSIM with a number; the Hall A counters close at 22:00. |
| Where the measurements dip | ||
| The KTX and SRT high-speed lines | SK Telecom or KT | The weakest place in Korea to stream, by the government's own numbers: 393 Mbps average 5G on high-speed rail and only 81% of rail measurements meeting the HD-video threshold, against about 98% everywhere else. 19 of the 32 weak-5G zones the ministry listed are rail sections. Expect drops in the long tunnels between Daejeon and Daegu; nothing you buy changes the tunnels. |
| Seoraksan and the Gangwon mountains | SK Telecom | The cable car and the main trails to Ulsanbawi are covered. The valleys beyond Biseondae are where the LG U+-riding plans go to no service first, because LG U+ has no 3G to fall back on. SKT's edge here is reputation rather than measurement, and we say so. |
| Jirisan and the Baekdudaegan ridge | SK Telecom | Shelters and ridge tops have signal; the forest sections between them are patchy on every carrier. Download the Naver Map area offline before the trailhead, and take the plan that names its network. |
| The DMZ tours: Imjingak, the Third Tunnel | Any, with a caution | The tourist sites are covered. Near the line your phone may see a North Korean network in the list; leave selection on automatic and do not join it. Inside the tunnel itself nothing works, which is the tunnel, not the eSIM. |
| Islands and water | ||
| Jeju: the coast, Seogwipo, the Olle trails | Any | Full 4G and 5G on all three carriers around the whole coast and on the Hallasan trails. The thing to know about Jeju is not coverage: it is that the airport has had no carrier counters since June 2026, so arrive with the eSIM installed. |
| Jeju interior and the oreum | SK Telecom | The volcanic cones and the interior roads between them are where travelers most often report a travel eSIM dropping to one bar. Coverage exists; the margin is thinner, and the network you cannot see is the one deciding it. |
| Ulleungdo, Dokdo and the East Sea ferries | KT | KT runs maritime LTE from island base stations that reaches about 100 km offshore and holds better than 10 Mbps mid-crossing on the Pohang route, and it runs LTE and 5G on Ulleungdo itself. No brand we can link publishes a KT agreement, so on this route the carriers' own eSIMs are the honest answer. |
| The west coast islands and Yeosu | Any near shore | Short crossings hold a signal from the shore towers on every carrier. Longer ferries lose everything mid-water except on KT's maritime coverage, and the small islands have one or two towers whose owner decides your week. |
Compiled from the Korean Ministry of Science and ICT's 2025 communications quality evaluation, Opensignal's December 2025 South Korea report, KT's published maritime coverage work, and traveler reports through September 2026. We have not walked these routes with a signal meter and we are not going to pretend otherwise. How we test.
Setting it up takes about four minutes before you fly
- Check the phone. Dial *#06#. If an EID appears, the phone takes an eSIM. If it is carrier-locked, sort that out first, because no eSIM works on a locked handset.
- Buy and install on home wifi. Install the profile before you fly. Do not plan to scan a QR code at Incheon: the plan does not start counting until it connects in Korea, so waiting saves you nothing and costs you a working phone at immigration and on the AREX.
- Land, then switch. Turn the eSIM line on for data, leave your home line on for calls and texts with data roaming off. That one toggle is what stops the $12-a-day charge, and it keeps your home number alive for the verification codes Korean apps send.
- If it will not connect, set network selection to manual and pick the carrier your plan rides: SK Telecom for Airalo. For Saily, GigSky and Yesim there is no published answer, so try each of the three. Full setup and the symptom-to-fix table.
South Korea eSIM questions answered straight
Which eSIM is best for South Korea in 2026?
Airalo for most trips: $19.00 for 10GB over 30 days with 5G, and the only brand we can link that names its Korean network, SK Telecom, which Opensignal rates best for coverage. GigSky at $17.79 if you are staying in the cities and want the cheapest 10GB. Saily if you stream or hotspot, for the published 5GB-a-day cap and a 4.7 Trustpilot score across 30,662 reviews. Checked September 7, 2026.
Should I get an eSIM for South Korea, or a SIM card at the airport?
An eSIM installed before you fly, for almost everyone. The airport counters at Incheon are real and open 24 hours in the main halls, but the same LG U+ or KT plan costs more at the counter than online, and Jeju airport has had no carrier counters at all since June 2026. The counter still makes sense in two cases: your phone has no eSIM slot, or you need a Korean 010 number. The SIM card page covers both.
Which SIM card is best for tourists in Korea?
If you mean a physical SIM, the three carriers' own tourist SIMs are the only real options and they are close: LG U+ is the easiest to buy online with a 010 number included, SK Telecom via its partner krsim is the cheapest for a week of uncapped data at $20.70, and KT is the one with maritime coverage on the East Sea. All three want your passport. If you mean any product at all, a travel eSIM from Airalo or GigSky is cheaper for data-only trips and needs no ID.
Is Airalo good for Korea?
Yes, and it is our default pick. Airalo's Korea eSIM, called Jjang, shows SK Telecom as its network on Airalo's own page, carries 5G, and sells the cheapest 5GB on this site at $10.00 for 7 days. The cons are real: $1.21 more than GigSky at 10GB, a 3GB-a-day cap on unlimited, and a 2025 traveler review reporting LG U+ on LTE only, which appears to have changed since. Airalo also pays us the lowest rate of the four brands we link.
Do I need a Korean phone number to use apps in Korea?
Less than you did a year ago. Naver Map needs no login. Kakao T accepts a US number. Naver Booking and Pay accept passport verification since June 2026. Baemin takes orders without a Korean number since summer 2026. CatchTable's international app uses email. Coupang and Coupang Eats still want a Korean-carrier SMS code, and some in-store waitlist kiosks still ask for a local number. The full list, and the three ways to get a 010 number if you need one.
Is 10GB enough for two weeks in Korea?
For most people, yes. Two weeks of Naver Map, KakaoTalk, Kakao T, Papago and photo uploads lands around 8 to 11GB if you use hotel and subway wifi in the evenings. 10GB is $17.79 from GigSky or $19.00 from Airalo on SK Telecom. If you will stream on the KTX or hotspot a laptop, go to 20GB from Yesim at $27.96 or read the unlimited caps above.
Which network does my Korea eSIM use?
If it is Airalo, SK Telecom, shown on Airalo's own page. If it is Ubigi or Holafly, SK Telecom and LG U+. If it is Nomad, SKT or KT depending on the plan. If it is Saily, GigSky or Yesim, the company does not say and we are not going to guess for them. In Seoul and Busan it does not matter. On the KTX, in the Gangwon valleys and on the East Sea ferries it starts to.
Does the SK Telecom hack from 2025 affect a tourist eSIM?
No. The April 2025 breach exposed SIM authentication data for existing SK Telecom subscribers, and SKT replaced their SIMs and added a protection service that covers roamers too. A travel eSIM issued in 2026 was never in that data. The September 2025 KT femtocell attack worked through Korean postpaid micropayment accounts, which a prepaid tourist line does not have. Both incidents are written up on the network page.
The only linkable eSIM that tells you it runs on SK Telecom
Airalo shows SK Telecom as its Korean network, sells 10GB for $19.00 over 30 days with 5G, and 5GB for $10.00, the cheapest 5GB on this page. It also pays us the lowest rate of the four brands we link. Both of those things are true, and the named network is why it is first.
See Airalo Korea plansSources & freshness: Plan prices pulled from esimdb.com and each brand's Korea product page on September 7, 2026, in USD, before promo codes. Airalo and Nomad geo-serve Canadian dollars from our connection, so their USD figures come from esimdb; Saily's Korea page returned a bot challenge, so every Saily figure is esimdb's. Yesim, Ubigi and Holafly figures are from their own pages in USD. Network claims from each brand's published Korea page on the same date; where a brand publishes nothing we say so. Carrier measurements from the Korean Ministry of Science and ICT's 2025 communications quality evaluation (released 30 December 2025) and Opensignal's South Korea report of December 2025. Carrier tourist eSIM prices from lguplus.com/korea-sim and krsim.net on September 7, 2026, in won and USD as published. Jeju airport counter closures from Korean press reporting of May 2026. App-verification changes from Naver's press release of 9 June 2026 and Korean press coverage of Baemin's August 2026 change. Trustpilot scores checked September 7, 2026. Prices move; we re-check monthly and date-stamp every table.