Travel eSIM guide: eSIM vs SIM vs roaming, by country
An eSIM is a data plan you download onto the chip built into your phone. No SIM swap, and your home number stays active while you use local data.
Country guides
eSIM vs SIM vs roaming
eSIM
- Install before you fly and get data the moment you land
- No shop queue or SIM tray; nothing to lose
- Keep your home SIM active for calls and SMS at the same time
- Usually cheaper than carrier roaming for data
- Needs an eSIM-capable, carrier-unlocked phone
- Most travel plans are data-only (no local phone number)
- Setup needs Wi-Fi or data at install time
- Deleting the profile usually means buying again
Physical SIM
- Works in older phones without eSIM
- Local SIMs bought in-country may include a local number
- Easy to hand over or swap between phones
- You must remove your home SIM (unless dual-SIM), so Korean SMS may not arrive
- Small card is easy to lose; needs a SIM pin
- Many countries require passport registration at purchase, sometimes with a face check
Carrier roaming
- No setup: keep your own number and SIM
- Calls and SMS on your usual number
- Simple for very short trips
- Usually the most expensive per GB
- Daily passes can add up on longer trips
- Speed or data caps may apply after a threshold
Check that your phone supports eSIM
- iPhone: iPhone XS, XS Max, XR and later support eSIM. iPhones sold in mainland China generally do not (Apple lists only iPhone 17e, iPhone Air and iPhone 18 Pro/Pro Max as eSIM-capable there); Hong Kong/Macau XS/XR variants also have no eSIM.
- Google Pixel: Pixel 4 and later support eSIM. Pixel 3/3a support depends on where and from which carrier they were bought.
- Samsung Galaxy: many models from the Galaxy S20 series onward support eSIM, but it depends on the country model. Galaxy phones sold in Korea support eSIM from Galaxy S23, Z Fold4, Z Flip4 and A Quantum4 onward. Galaxy phones from mainland China, Hong Kong, Taiwan and Macau generally lack eSIM.
- Quick check: dial *#06#. If an EID (32-digit number) is shown, the phone has eSIM hardware.
- Carrier lock: the phone must be unlocked. On iPhone, Settings > General > About should show 'No SIM restrictions' next to Carrier Lock.
- On Galaxy, go to Settings > Connections > SIM manager; if 'Add eSIM' appears, eSIM is supported.
How much data do you need?
Pick a plan of about 3.6 GB
Install on iPhone
- Connect to Wi-Fi before departure.
- Go to Settings > Mobile (Cellular) > Add eSIM.
- Choose 'Use QR Code' and scan the code from your provider, or tap 'Enter details manually' and type the SM-DP+ address and activation code.
- Label the new line (e.g. 'Travel') and keep your home line as the default for calls and SMS.
- Set 'Mobile Data' to the travel line.
- On arrival, turn on the travel line and switch Data Roaming ON for that line only.
- Turn Data Roaming OFF for your home line if you want to avoid carrier roaming charges; SMS can still arrive on the home line.
Install on Android (Samsung Galaxy)
- Connect to Wi-Fi before departure.
- Samsung Galaxy: Settings > Connections > SIM manager > Add eSIM. (Pixel: Settings > Network & internet > SIMs > Add SIM.)
- Choose 'Scan QR code from service provider' and scan, or enter the activation code manually.
- In SIM manager, set Mobile data to the travel eSIM and keep Calls/Text on your home SIM.
- On arrival, turn on the travel eSIM and enable Data roaming (Settings > Connections > Mobile networks > Data roaming).
- Leave data roaming off on your home SIM to avoid roaming charges.
Before you fly
- Install the eSIM at home on Wi-Fi; activate it (and turn on its data roaming) after landing. Check your plan: some start the validity clock on install, others on first connection.
- Do not delete the eSIM profile until the trip is over; most profiles cannot be re-downloaded.
- Keep your Korean line on for SMS. SKT and KT state that receiving SMS while roaming is free; check with other carriers and MVNOs. Bank and card verification texts usually arrive this way.
- Hotspot/tethering is allowed on some plans and blocked on others; check before you buy.
- Most travel eSIMs are data-only. Use messaging apps for calls, and check whether a local number is needed for taxi or delivery apps.
- If there is no signal after landing, toggle airplane mode, check that data roaming is on for the travel line, and select the network manually if needed.