When moving to or visiting Korea, one of the first things you’ll need is mobile connectivity.
As of 2025, Korea offers two main types of SIM technology: the traditional physical USIM and the newer eSIM. For foreigners—whether you're here to study, work, or travel—it’s essential to understand which option suits your needs, your device, and your budget.
In this guide, we’ll walk you through everything: how eSIM and USIM work in Korea, which devices are compatible, the best providers, how to activate them, and key pros and cons of each. Whether you're a digital nomad, exchange student, or long-term expat, you’ll find all the info you need here.
Table of Contents :
- What Is a USIM?
- What Is an eSIM?
- USIM vs eSIM Comparison Table
- Device Compatibility in Korea
- Types of Mobile Plans for Foreigners
- How to Get a SIM in Korea
- Where to Buy: Top Providers in Korea
- Data Speeds and Coverage
- Cost Comparison
- Troubleshooting Common Issues
- Frequently Asked Questions
- Extra Tips for Choosing the Right SIM
- Future Trends in Korea's SIM Market
What Is a USIM?
A USIM (Universal Subscriber Identity Module) is a physical SIM card that stores your mobile subscriber information. It allows your phone to access Korea’s cellular network. This is the standard SIM most users are familiar with.
☑️ Where to Get One:
Carrier stores (SK Telecom, KT, LG Uplus)
Airports
Online retailers
Convenience stores
☑️ Requirements:
Passport or ARC (Alien Registration Card)
Sometimes a Korean phone number or address
☑️ Setup:
Insert the SIM physically into your phone’s tray
Follow activation instructions (usually provided on paper or via SMS)
☑️ Pros:
Compatible with almost all devices
Easy to use, swap between devices
☑️ Cons:
Can be lost, stolen, or damaged
Insertion/removal can be annoying
What Is an eSIM?
An eSIM (Embedded SIM) is a programmable chip built into newer smartphones and tablets. Instead of inserting a card, you download a SIM profile from your carrier.
☑️ How It Works:
Check if your device supports eSIM (iPhone XS and later, Samsung S20+, etc.)
Purchase a plan from a carrier or eSIM provider
Scan a QR code or install via app (e.g. SKT, KT, LG U+)
☑️ Pros:
No physical card required
Dual SIM functionality (one eSIM + one USIM)
Easily switch between carriers or plans
☑️ Cons:
Limited device support
Requires more tech know-how to activate
Transferring eSIM to a new phone isn’t as easy
USIM vs eSIM Comparison Table
| Feature | USIM | eSIM |
|---|---|---|
| Form | Physical card | Digital chip (built-in) |
| Compatibility | Almost all phones | Only newer phones/tablets |
| Flexibility | Must replace SIM to switch | Can store multiple profiles |
| Risk of Damage | Yes | No |
| Dual SIM Support | Limited | Excellent |
| Setup Complexity | Low | Medium |
Device Compatibility in Korea (2025)
🔳 Apple Devices:
iPhone XS, XR, 11 and newer (including SE 2020+)
iPad Pro, iPad Air (2021+)
🔳 Samsung:
Galaxy S20, S21, S22, S23 series
Z Flip and Z Fold (2020+ models)
🔳 Google:
Pixel 3 and newer (excluding US Verizon models)
Tip: Korean-bought phones may be carrier-locked. If you're using your home country’s device, make sure it's unlocked.
Types of Mobile Plans for Foreigners
🔳 Prepaid Plans:
No contract
Ideal for tourists, students, short stays
Buy online or at airport kiosks
🔳 Postpaid Plans:
Monthly billing
Better data/voice rates
Requires ARC, Korean bank account
✔️ Documents Needed:
Passport (for prepaid)
ARC + bank account (for postpaid)
Korean phone number (if applying online)
How to Get a SIM in Korea
🔳 For USIM:
Go to a carrier store or partner kiosk
Show ID (passport/ARC)
Choose a plan (data-only, voice+data, etc.)
Receive and insert SIM
Complete activation in-store or via SMS
🔳 For eSIM:
Check compatibility
Buy plan online or at carrier branch
Get QR code or activation code
Use phone settings → add eSIM → scan QR
Activate and confirm with SMS or email
✔️ Most activations complete in under 10 minutes.
Where to Buy: Top Providers in Korea
Broadest coverage nationwide
Offers both USIM and eSIM
Store locator in English available online
🔳 KT
Good prepaid plans
English customer service (limited)
Frequent traveler options
🔳 LG Uplus
Great speeds in urban areas
Simplified eSIM support through app
🔳 eSIM Global Providers:
- Airalo: Instant activation, data-only
- Holafly: Unlimited data options
- Nomad: Flexible duration and pricing
Pro Tip: Global providers are great for tourists. For long-term residents, consider Korean carriers for better value.
Data Speeds and Coverage
Korea has one of the fastest networks in the world. All three major carriers support 5G and LTE nationwide, but speeds and stability vary:
| Provider | LTE Speed | 5G Speed | Urban Coverage | Rural Coverage |
| SK Telecom | Excellent | Excellent | ★★★★★ | ★★★★☆ |
| KT | Great | Very Good | ★★★★☆ | ★★★★☆ |
| LG Uplus | Great | Great | ★★★★☆ | ★★★☆☆ |
Cost Comparison (2025)
| Plan Type | USIM Price | eSIM Price | Monthly Data (avg) |
| Prepaid Basic | ₩33,000 | ₩30,000 | 3GB–5GB |
| Unlimited | ₩55,000+ | ₩50,000+ | Unlimited |
| Tourist SIM | ₩27,000 | ₩25,000 | 7-day, 1GB/day |
✔️ eSIMs are slightly cheaper due to no physical card production costs.
Troubleshooting Common Issues
☑️ USIM Problems:
SIM not recognized → Reinsert or clean tray
No service → Carrier activation pending
Poor data → Check APN settings
☑️ eSIM Problems:
QR won’t scan → Restart device or use manual input
eSIM missing after update → Reinstall profile
Switching phones? → Contact provider to reissue QR
Frequently Asked Questions (FAQs)
Q1. Can I use both eSIM and USIM in one device?
Yes! Many phones allow dual SIM (eSIM + USIM). Great for travelers.
Q2. Can I buy a SIM before arriving in Korea?
Yes. Some eSIM providers offer instant delivery. Or order USIM from online shops with airport pickup.
Q3. Is eSIM available for prepaid plans?
Yes, most major carriers now support prepaid eSIMs.
Q4. Can I change from USIM to eSIM?
Yes. Visit your carrier to request an eSIM transfer.
Q5. Is eSIM safe for long-term use?
Yes, it’s encrypted and managed securely. Suitable for both short and long stays.
Extra Tips for Choosing the Right SIM
🔳 Consider Your Travel Habits
If you frequently travel between countries, eSIM can be more convenient since it allows you to switch plans without swapping physical cards. Many global eSIM providers also let you manage multiple country profiles from a single app.
🔳 Always Keep Backup Info
Take screenshots or print out your eSIM QR code and carrier settings in case you need to reinstall. If you're using a USIM, keep the SIM card packaging and activation receipt.
🔳 Check for SIM Lock
If you bought your device through a Korean carrier, make sure it’s not locked to that carrier. Even phones bought abroad may not support eSIM features with Korean networks unless they’re fully unlocked.
🔳 eSIM + USIM = Great Combo
Dual SIM capability can be a lifesaver. Many expats use their home country’s number on a USIM and a Korean data plan via eSIM—or vice versa. It’s especially useful for banking, receiving verification texts, and staying in touch with both local and international contacts.
Future Trends in Korea's SIM Market
South Korea is rapidly expanding its digital infrastructure, and more mobile carriers are expected to adopt eSIM as the default option in the next few years.
By 2026, all three major Korean carriers are expected to offer full eSIM support for both prepaid and postpaid users.
IoT devices and smartwatches will rely more heavily on eSIM for seamless integration.
The Korean government has also announced support for “remote provisioning” to make it easier to switch between telecom providers without visiting stores.
✔️ In the future, foreigners might be able to register for eSIM completely online, using passport verification and facial recognition without needing an ARC.
In 2025, both eSIM and USIM are good choices for mobile connectivity in Korea. eSIM is great for flexibility, while USIM offers broad device support.
Make sure your phone is unlocked, and compare plans based on your stay. For help, visit a telecom store—many have English-speaking staff in major cities.
