- Key point: Verify that the phone is unlocked, eSIM-compatible and supports the Korean network before purchase.
- Price: Compare data allowance, validity, voice or SMS support, hotspot rules, refund terms and support access.
- Tip: Install on reliable Wi-Fi, preserve the QR code and instructions, label both SIMs and keep an offline backup route.
Typical issuance fees are approximately KRW 2,750 for eSIM and KRW 7,700–8,800 for a physical USIM, before plan charges. Device support and operator terms determine which option works.
Install an eSIM profile before arrival when supported, but do not delete the QR code or home line prematurely. For a physical USIM, reserve ahead during peak travel periods when airport stock and queues can tighten.
Still deciding between eSIM, SIM or pocket Wi-Fi?
This guide covers installing and activating a plan once a format is chosen. For a full side-by-side comparison of network, Korean-number inclusion, group sharing and pickup/return, see Korea eSIM vs SIM vs pocket Wi-Fi first.
Verify the phone before paying
- Confirm that the exact device model supports the required eSIM or SIM technology.
- Confirm that the phone is carrier-unlocked. An EID shown in device settings or by a device-information code can indicate eSIM hardware, but the menu and code vary by manufacturer and region.
- Check whether the plan provides data only or also a Korean phone number. Data access does not guarantee that every Korean service will accept the number for identity verification.
- Read when the validity clock begins: purchase, installation, first network connection or a selected date.
Prepare and activate without losing the QR code
- Purchase through a carrier or seller whose network, refund terms and support details are clearly stated.
- Save the QR code, manual activation values (SM-DP+ address and activation code) and support contact somewhere available offline, not only as a screenshot inside a messaging app.
- Install through the phone's own cellular/eSIM settings menu while connected to reliable Wi-Fi, following the seller's timing instructions — not by opening the QR code in a camera or photo app, which can mark it as used without completing installation.
- After arrival, select the travel line for mobile data and enable data roaming only if the plan specifically requires it.
- Test maps and messaging before leaving the airport. Do not delete an eSIM profile while troubleshooting unless the provider confirms it can be reissued.
Fix common activation errors
Most tourist eSIM and SIM problems trace back to one of a few causes. Work through the one that matches before contacting support.
"QR code already used" or the scan fails
A tourist eSIM QR code is normally single-use. Opening it in a camera app, screenshotting and reopening it, or an earlier partial install can mark it used even without a completed activation. Ask the seller for a fresh QR code or the manual SM-DP+ address and activation code, then install through the phone's cellular settings menu rather than the camera.
Installed, but shows "No Service" or "SOS only"
Check that the new line is actually selected for mobile data in the phone's cellular settings — installing an eSIM does not automatically make it the active data line. Toggle airplane mode on and off to force the phone to re-register with the network, and confirm data roaming is set the way the specific plan requires (some tourist eSIMs need roaming on, others activate it automatically).
A second SIM is blocking the new line
On a dual-SIM phone, a home-country SIM can keep intercepting data or getting selected as primary. Set the Korea line as the default for mobile data specifically, and turn off data roaming on the home line rather than removing it, so calls and texts on the home number can still work.
Phone reports the eSIM is not supported, mid-trip
Some devices restrict additional eSIM installs by region or carrier policy even when unlocked for calls and texts. This is a device-level restriction rather than a plan problem — check the seller's stated device requirements again and contact their support with the exact error text.
Accidentally deleted the eSIM profile
Most tourist eSIMs install once per device and cannot be reinstalled from the same QR code after deletion. Contact the seller's support immediately with the order reference; reissue is at their discretion and is not guaranteed, so avoid deleting a working profile while troubleshooting something else.
Keep an arrival-day backup
Download the hotel address and first route, keep airport Wi-Fi instructions, and save the carrier counter location and opening hours. Korea Tourism Organization lists airport and city convenience-store SIM sales as well as official roaming sites for KT, SK Telecom and LG U+. Inventory, plan names and hours can change, so verify them directly before arrival.
Official sources
Time-sensitive details were checked against the original sources below on 2026-08-28.