Quick answer: Choose an eSIM if your unlocked phone supports it, a physical SIM if compatible with your device, or pocket Wi-Fi if sharing one connection suits your group. Compare the actual plan rather than the format alone.
Check compatibility first
Confirm the exact phone model, market version and carrier-lock status before buying. A physical foreign SIM does not solve a carrier lock. If your home carrier cannot unlock the phone, compare its roaming service with a separate Wi-Fi device.
Keep access to your usual number if you need bank verification messages. Check your home carrier's roaming settings and costs rather than assuming that retaining a SIM is free to use abroad.
eSIM: convenient, but read activation rules
An eSIM is downloaded to a supported phone. The plan may begin at installation, activation, a selected date or first network connection. Follow that provider's instructions; “install now, activate on landing” is not a universal rule.
Check whether the plan is data-only or includes a Korean number, incoming messages and outgoing calls. Some eSIM products include voice service, so the previous statement that only physical SIMs can provide a local number was incorrect.
Physical SIM: useful for compatible phones
Check whether collection is available at your arrival terminal and during your landing hours. Bring the identification required by the seller. Keep your original SIM in a safe labelled holder so it is easy to restore after the trip.
A tourist number is not the same as Korean resident identity verification. KT's tourist service has entry-verification conditions for voice/SMS features. Confirm the specific service you need before buying; an app requiring resident verification may still be unavailable.
Pocket Wi-Fi: think about the group
A shared device can suit travellers who stay together and use several devices. It becomes less convenient when people split up, because only those near the router remain connected. Compare battery life, charging, connected-device limits, deposit, loss charges and the return location.
Compare plans on the same basis
- Duration and the exact start of validity.
- High-speed allowance, speed after the allowance and fair-use limits.
- Hotspot/tethering support and number of devices.
- Calls, SMS and any identity-verification restrictions.
- Final price, cancellation policy and support hours.
- Coverage for the actual islands, rural areas or trails you will visit.
“Unlimited” may still include a high-speed limit. We removed stale price tables rather than implying they are current provider quotes.
Prepare before departure
Save your hotel address and key routes offline where possible. Download navigation and translation apps in advance, and keep setup instructions somewhere you can open without mobile data. Use airport Wi-Fi if you need to contact the provider, but leave time to resolve activation before travelling onward.