TL;DR — 3 things to know before you buy
- Airalo uses the KT network, LTE only — no 5G. It's cheap and works fine for maps/messaging, but it's data-only (no Korean 010 number) and can't receive SMS verification codes from Korean apps.
- Saily auto-selects the best available carrier and supports 5G. Built by the NordVPN team, cleaner app. Still data-only — same SMS verification limitation as Airalo.
- Average LTE speeds vary more than older reports suggest. KT leads at ~234 Mbps average, SKT ~128 Mbps, LG U+ ~36 Mbps in recent testing — but all feel fast enough for everyday use. Your location (underground, rural, dense buildings) still matters far more than which carrier you pick.
⚠️ Critical — The 010 Number Problem
Third-party eSIMs (Airalo, Saily, Holafly, Nomad) are data-only — no Korean phone number.
Every Korean app that sends a 6-digit SMS code — Baemin, Coupang Eats, KakaoTaxi, concert ticket sites — will fail at account creation without a Korean 010 number.
If you want to use Korean apps: buy an eSIM directly from KT, SKT, or LG U+ at the airport booth. You'll get a real 010 number. It costs more (~₩33,000–₩70,000) but solves the verification problem completely.
Every Korean app that sends a 6-digit SMS code — Baemin, Coupang Eats, KakaoTaxi, concert ticket sites — will fail at account creation without a Korean 010 number.
If you want to use Korean apps: buy an eSIM directly from KT, SKT, or LG U+ at the airport booth. You'll get a real 010 number. It costs more (~₩33,000–₩70,000) but solves the verification problem completely.
Provider-by-Provider Breakdown
What each eSIM option actually gives you — no marketing speak.
Airalo — Korea eSIM
KT Network · LTE Only
Best for: Budget travellers who only need internet for navigation and messaging.
Price: From ~$4 USD for 1GB/3 days; ~$20 for 10GB/30 days. Check the Airalo app for current pricing as plans vary.
5G: No. LTE-only, even in 5G coverage areas.
Korean 010 number: No. Data-only.
Registration: No passport needed. Buy and install via app before departure.
App quality: Large selection of plans, widely used globally. Interface functional but crowded.
⚠ Data-only · No 5G · Good price
Price: From ~$4 USD for 1GB/3 days; ~$20 for 10GB/30 days. Check the Airalo app for current pricing as plans vary.
5G: No. LTE-only, even in 5G coverage areas.
Korean 010 number: No. Data-only.
Registration: No passport needed. Buy and install via app before departure.
App quality: Large selection of plans, widely used globally. Interface functional but crowded.
Saily — Korea eSIM
Auto-selects Carrier · 5G Capable
Best for: Travellers who want a polished app experience and 5G where available.
Price: ~$10.99 for 5GB; competitive with Airalo on larger plans.
5G: Yes — auto-connects to best available carrier including 5G bands.
Korean 010 number: No. Data-only.
Registration: No passport needed. Buy and install via app.
App quality: Clean, minimalist. Built by the NordVPN team. Easy plan management.
✓ 5G · Clean app · Auto-carrier
Price: ~$10.99 for 5GB; competitive with Airalo on larger plans.
5G: Yes — auto-connects to best available carrier including 5G bands.
Korean 010 number: No. Data-only.
Registration: No passport needed. Buy and install via app.
App quality: Clean, minimalist. Built by the NordVPN team. Easy plan management.
Nomad / esimNB / Holafly
Various Networks · 5G Available
Best for: Specific needs — Nomad for 5G, Holafly for unlimited data plans.
Price: Varies; Holafly unlimited from ~$27/30 days.
5G: Nomad and esimNB support 5G. Holafly varies by plan.
Korean 010 number: No. All are data-only.
Registration: App-based, no passport required.
ℹ Data-only · 5G available · Check plan
Price: Varies; Holafly unlimited from ~$27/30 days.
5G: Nomad and esimNB support 5G. Holafly varies by plan.
Korean 010 number: No. All are data-only.
Registration: App-based, no passport required.
KT / SKT / LG U+ — Carrier eSIM
Direct Carrier · Voice + Data
Best for: Anyone who wants to use Korean apps requiring SMS verification.
Price: ₩33,000–₩70,000 at airport booth (10–30 day plans).
5G: Yes — real 5G where coverage exists.
Korean 010 number: Yes. Passes SMS verification for Korean apps.
Registration: Passport required at airport booth. Takes 5–10 minutes.
Where: Incheon Airport T1 / T2 arrival halls. Also available at carrier stores citywide.
✓ 010 Number · 5G · App verification works
Price: ₩33,000–₩70,000 at airport booth (10–30 day plans).
5G: Yes — real 5G where coverage exists.
Korean 010 number: Yes. Passes SMS verification for Korean apps.
Registration: Passport required at airport booth. Takes 5–10 minutes.
Where: Incheon Airport T1 / T2 arrival halls. Also available at carrier stores citywide.
Speed Reality Check — Carrier vs Location
Verified average LTE download speeds. The difference between carriers is smaller than you think.
Speed figures are averages — your experience varies by location. All three carriers feel fast enough for maps, streaming, and messaging in cities. Being underground (subway), inside concrete buildings, or in rural areas will cut speeds far more than any carrier difference. KT leads in recent speed tests; LG U+ averages are lower but still functional for everyday travel use.
"I ran SpeedTests on both Airalo (KT) and a proper KT SIM I bought at the airport — the speeds were nearly identical in Seoul. The only real difference was Airalo being LTE while my airport SIM could hit 5G near major stations. For YouTube and Maps they felt the same."
r/koreatravel · score 187 · March 2026
Full Comparison Table
Every major factor compared across providers. As of June 2026.
| Feature | Airalo | Saily | Nomad | Carrier Direct(KT/SKT/LGU+) |
|---|---|---|---|---|
| Network | KT only | Auto-selects best | Multiple | Native carrier |
| 5G support | ✗ LTE only | ✓ Yes | ✓ Yes | ✓ Yes |
| 010 number | ✗ None | ✗ None | ✗ None | ✓ Real 010 |
| SMS verification | ✗ Fails | ✗ Fails | ✗ Fails | ✓ Works |
| Price (10GB/30d) | ~$20 USD | ~$22 USD | Varies | ₩55,000–70,000 |
| Pre-arrival setup | ✓ Yes (app) | ✓ Yes (app) | ✓ Yes (app) | Airport only |
| Passport needed | No | No | No | Yes (at booth) |
| App quality | Good | Excellent | Good | Carrier app varies |
| Best for | Budget, data-only | Convenience + 5G | 5G priority | Korean app users |
How to Activate a Korea eSIM
Works for both third-party (Airalo/Saily) and carrier (KT/SKT) eSIMs. Check prerequisites before you travel.
Before You Travel — Checklist
✓ Check for eSIM support
Go to Settings → General → About and look for an "EID" field. If it's there, your phone supports eSIM. Alternatively: most iPhones XS (2018) or newer support eSIM. Samsung Galaxy S20 or newer. Most flagship Androids from 2021+.
✓ Confirm your phone is unlocked
Carrier-locked phones (common in the USA) install the eSIM profile but block activation. Contact your home carrier to unlock — this typically takes 1–5 business days. Do this before travel.
✓ Have internet when installing
You need an existing internet connection to download the eSIM profile. At home WiFi is ideal. If installing at the airport, use Incheon Airport free WiFi (network: "Incheon Airport", no password).
Step-by-Step Activation
1
Purchase the eSIM via app or booth
Third-party (Airalo/Saily): open the app, search "South Korea", choose a plan, pay. You'll receive a QR code or automatic profile download. Carrier (KT/SKT/LGU+): visit the airport booth with your passport, select a plan, pay. Staff generate the QR code on-screen.
2
Install the eSIM profile
iPhone: Settings → Cellular → Add Cellular Plan → "Use QR Code" → scan
Samsung: Settings → Connections → SIM Manager → Add Mobile Plan → scan
Pixel/other Android: Settings → Network & Internet → Mobile network → Add carrier → scan
Profile downloads in 30–60 seconds.
Samsung: Settings → Connections → SIM Manager → Add Mobile Plan → scan
Pixel/other Android: Settings → Network & Internet → Mobile network → Add carrier → scan
Profile downloads in 30–60 seconds.
3
Set as default data line
When prompted, set the Korea eSIM as your primary data plan. Leave your home SIM active for calls/WhatsApp, but disable data on your home SIM to avoid roaming charges. Dual-SIM setup: one line for calls, one for data.
4
Wait for activation (up to 15 minutes)
The carrier name appears in your status bar when activated. For third-party eSIMs, activation is instant once in Korea. For carrier eSIMs purchased at the airport, it may take 5–15 minutes for the network to fully provision your line.
5
Verify your connection (and 010 number if applicable)
Open a browser and load any page. For carrier eSIMs with a 010 number: dial *114 to hear your Korean number confirmed. Take a screenshot for app registrations.
Common Failure Points
The problems that appear most in Reddit trip reports — and how to fix them.
FAIL "eSIM profile installed but no signal / stuck on 'No Service'"
Almost always: your phone is carrier-locked. The eSIM profile downloads successfully but the phone rejects it at network registration. Fix: contact your home carrier and request an unlock. US carriers (AT&T, Verizon, T-Mobile) require 1–5 business days. Do this before your trip. If at the airport now, try a physical SIM from the same carrier — some locked phones accept physical SIMs from certain networks.
FAIL "Airalo shows connected but apps say 'verification failed'"
This is expected — Airalo is data-only with no Korean 010 number. Korean apps need to send an SMS code to a Korean number. Data-only eSIMs cannot receive these. Fix: go to the airport KT, SKT, or LG U+ booth and purchase a voice+data eSIM or physical SIM. The Airalo plan can remain installed as a backup data line.
FAIL "My eSIM worked yesterday but now shows 'No Service'"
Most common: your plan expired, or you've entered a building with poor penetration. Check your plan expiry date in the app. If the plan is still active, toggle Airplane Mode on and off to force a new network registration. If in a basement or elevator, go to street level and check again.
FAIL "Saily says 'auto-connecting' but never connects"
APN settings may not have been applied automatically. Go to Saily app → the Korea plan → Manual Configuration, and follow the APN setup instructions. On iPhone, this is usually automatic. On some Android phones, you may need to manually enter: APN name
internet, leave username/password blank.
FAIL "I bought a carrier eSIM at the airport but it's not activating"
Wait up to 15 minutes and stay connected to airport WiFi. Carrier eSIM provisioning can take time. If still not working after 15 minutes: (1) Toggle Airplane Mode off and on. (2) Restart the phone. (3) Return to the carrier booth — staff can re-push the eSIM profile or check registration status.
Frequently Asked Questions
Airalo works for basic data use in Korea — it runs on the KT network and provides solid LTE speeds in most areas. The main limitations: it's LTE-only (no 5G, even in 5G coverage areas) and it's data-only (no Korean 010 phone number). Without a 010 number, you can't receive SMS verification codes from Korean apps like Baemin, KakaoTaxi, or Coupang Eats. If you only need internet for Google Maps, messaging home, and browsing, Airalo is a cost-effective choice. If you want to use Korean apps, buy a carrier eSIM at the airport.
Airalo does NOT support 5G in Korea — it's KT network, LTE only. Providers that support 5G include Saily (auto-selects carrier, connects to 5G where available), Nomad, and esimNB. That said, in most tourist areas — subway stations, shopping streets, hotels — LTE speeds are 150–200 Mbps, fast enough that you won't notice a difference in daily use. 5G mainly matters for large downloads or 4K video streaming.
Third-party eSIMs (Airalo, Saily, Holafly) are data-only: internet access, no Korean phone number. Cheaper ($10–$27 USD), can be purchased and installed before arrival. Carrier eSIMs (KT, SKT, LG U+ at the airport) give you a real Korean 010 number plus data. The 010 number is required for SMS verification on Korean apps. If you plan to use food delivery, taxi, or ticket apps, the carrier eSIM is worth the extra cost (~₩33,000–₩70,000 depending on plan length).
For most travellers, Saily has an edge for Korea: it auto-selects the best available carrier (not locked to KT like Airalo), supports 5G, and has a cleaner, more modern app — built by the NordVPN team. Airalo has a larger plan selection and is sometimes slightly cheaper. Both are data-only with no 010 number. Verdict: choose Airalo if price is your top priority; choose Saily if you want a better app experience and 5G where available.
All three major carriers (SKT, KT, LG U+) cover major urban areas well. Recent speed testing shows KT averaging ~234 Mbps, SKT ~128 Mbps, and LG U+ ~36 Mbps on LTE — a wider gap than older reports suggest, though all are fast enough for everyday travel. Your physical location (underground, concrete buildings, rural areas) matters more than the carrier difference. For travel outside major cities, KT has the widest rural and island coverage.
Yes — for third-party eSIMs (Airalo, Saily, Nomad), you can purchase and install the eSIM profile at home before your flight. It activates automatically once your phone connects to a Korean tower. This saves time at the airport. Carrier eSIMs (KT/SKT/LG U+) must be purchased in Korea — at the airport booth or a carrier store — unless you use the carrier's international website to pre-order (less convenient, not all carriers support this).