Korea eSIM buying and setup guide

1 · Buy by allowance

How to choose between 3GB, 10GB, and 20GB

Datatua’s Korea range uses fixed allowances. There is no honest universal formula that converts a gigabyte into a certain number of travel days: navigation, cloud photo uploads, video, app updates, background sync, and tethering can change consumption dramatically. Start with your own phone’s recent cellular-data history and compare the three allowances relative to each other.

Before departure, reset or note your device’s cellular usage counter if you want a clearer trip-only reading. Phone counters can differ from a provider’s accounting, so treat them as a practical indicator rather than a billing record.

2 · Read the clock correctly

Plan validity is not the same as trip length

The contractual validity periods are 15 days for the 3GB plan and 30 days for both the 10GB and 20GB plans. The validity window starts when the eSIM first connects to a supported Korean mobile network. The data allowance and the validity clock are separate limits: service ends when the applicable plan condition is reached, and unused data is not a reason to assume the clock will extend.

A seven-day itinerary can use a 15-day or 30-day plan. A 20-day itinerary cannot use the 15-day plan for all 20 days merely because data remains. Likewise, choosing a 30-day plan for a short trip does not create a daily data entitlement. Pick an allowance based on expected total use, then check that the validity window covers the dates after first connection in Korea.

3 · Check the phone

You need eSIM support and an unlocked device

Model name alone is not enough. Regional variants, the original selling carrier, and software can affect eSIM availability. Before sending a request, confirm that the phone shows an option to add an eSIM and that it is not locked to your home carrier.

• iPhone: Apple says an unlocked iPhone shows “No SIM Restrictions” at Settings → General → About → Carrier Lock. Apple’s travel-eSIM guidance generally covers iPhone XS, XS Max, XR, and later, but regional exceptions exist. Read Apple’s current travel eSIM instructions for the device you will carry.
• Google Pixel: Google directs users to Settings → Network & internet → SIMs → Add SIM → Set up an eSIM. If the phone came from a carrier, Google recommends confirming eSIM support and the device IMEI with that carrier. See Google’s Pixel eSIM setup guide.
• Samsung Galaxy: supported models expose Settings → Connections → SIM manager → Add eSIM. Samsung notes that menus and availability can vary by device, software, carrier, and market. Check Samsung’s Galaxy SIM and eSIM guide and confirm the exact model with your current carrier.

If the add-eSIM menu is missing or the carrier cannot confirm that the phone is unlocked, stop before requesting a plan. Datatua cannot remotely remove a carrier lock or add eSIM hardware to an unsupported device.

4 · Know what data-only means

No Korean phone number or SMS verification

These Korea plans provide mobile data only. They do not include a Korean telephone number, standard voice minutes, or SMS. You cannot use the Datatua line to receive a Korean verification text, complete a service that requires identity verification with a Korean mobile number, or make a normal carrier voice call.

Internet-based messaging and calling can work over mobile data when the relevant app and account permit it. Your home SIM can remain installed for its number, but your home carrier may charge for calls, messages, or roaming. Datatua does not control those fees. Review your home carrier’s settings and prices before leaving, and disable roaming on the home line if you do not intend to use it abroad.

5 · Install before departure

How to import the eSIM QR safely

Complete the request and compatibility review first. When a confirmed order provides a QR, use reliable Wi-Fi and keep the QR available on a second screen or printed page. Do not publish it, forward it casually, or repeatedly scan it on different phones. An eSIM QR is an activation credential, not a promotional image.

Keep the travel line off—or leave it installed without selecting it for mobile data—until you are ready to connect in Korea. Do not delete a successfully installed profile merely because it has not connected outside Korea; a replacement QR may require support.

6 · Configure on arrival

Select the travel line and check data roaming

After arrival, turn on the Datatua eSIM, select it as the phone’s mobile-data line, and enable data roaming for that travel line when required. Travel eSIMs commonly use a roaming relationship to reach a supported local network; the phone’s roaming switch can therefore be necessary even though the Datatua plan itself has a fixed allowance.

• iPhone: choose the Datatua line under Cellular Data, then open that line’s Cellular Data Options and turn on Data Roaming. Apple’s roaming settings guide documents the path.
• Pixel: under Settings → Network & internet → SIMs, make sure the travel SIM is in use, mobile data is assigned correctly, and Roaming is on when needed. Google documents these controls in its mobile-data guide.
• Galaxy: select the travel eSIM for mobile data in SIM manager, then check Settings → Connections → Mobile networks → Data roaming. Samsung notes that labels can vary by carrier and software in its connection settings guide.

If both home and travel lines stay active, turn off cellular-data switching unless you explicitly want the phone to fall back to the home line. Keep data roaming off on the home line to reduce the risk of an unintended home-carrier charge. Network name, radio technology, and speed can change with device, location, terrain, and congestion.

7 · Troubleshoot without deleting

If the eSIM does not connect in Korea

1. Connect to Wi-Fi so you can keep this guide and your order page available.
2. Confirm that the Datatua eSIM is installed and the line is turned on.
3. Confirm that the Datatua line—not the home SIM—is selected for mobile data.
4. Turn on data roaming for the Datatua line and keep it off for the home line.
5. Leave network selection on automatic unless support gives a specific instruction.
6. Toggle Airplane Mode on for about 30 seconds, then turn it off and allow the phone time to search again. Apple includes this step in its official roaming troubleshooting.
7. Restart the phone and re-check the line and mobile-data settings.
8. Do not delete the eSIM or repeatedly rescan the QR. Preserve the profile and contact support with the order reference, phone model, and a description of the status shown.

8 · Keep the order recoverable

Use the same Datatua account for status and QR recovery

The order belongs to the customer account that created it. Sign in with that account on My Page to review owned orders and reopen the order-status path. Do not share an order link or QR publicly. If you lose access to the account, use the account recovery flow rather than creating a second request for the same installation.

A submitted plan request is not a completed purchase and does not by itself mean an eSIM has been provisioned. Check your order status for its actual progress; do not assume the travel line is ready until your installation details are available.