Kimchi Korea + Japan eSIM for a Combined Trip
For a trip that covers both Korea and Japan, the cleanest setup is two separate data eSIMs: one Korea eSIM and one Japan eSIM, both installed before you fly. You switch from one to the other in your phone’s settings the moment you land in each country, and both are data-only, with no Korean or Japanese phone number and no SIM card to swap. A single regional “Asia” eSIM also exists and can work, but on a two-country trip it usually buys convenience at the cost of slower speeds, smaller data caps, and less control over which network you ride. This guide walks through both routes, the on-arrival switch, and which one fits your itinerary.
Last updated: June 2026. General travel information, not legal, immigration, or banking advice; carrier terms and visa rules change, so confirm current details before you rely on them.
Should you buy two country eSIMs or one regional eSIM?
For most Korea-plus-Japan trips, two dedicated country eSIMs beat one regional eSIM on speed and value. A regional plan is genuinely simpler, since it is one purchase and one profile, but it typically roams onto a partner network in each country instead of connecting as a local line. That can mean lower priority on congested towers and a higher per-gigabyte price. Two country eSIMs let each one connect to a strong local network: Kimchi Mobile’s Korea eSIM runs on KT’s nationwide network, and the Japan eSIM connects to a local Japanese network when you land in Japan.
The trade-off is real but small. With two eSIMs you do one extra thing on arrival: open Settings and switch which line is in use. It takes about twenty seconds. Here is how the two routes compare.
| Factor | Two country eSIMs | One regional eSIM |
|---|---|---|
| Local network in each country | Yes | Usually roaming |
| Data-only (no phone number) | Yes | Yes |
| Switch needed on arrival | Yes, 20 sec | No |
| Typical per-GB value | Better | Often pricier |
| Separate data pools per country | Yes | Shared pool |
Pick the regional eSIM if you genuinely will not touch your settings and you only need light browsing in each country. Pick two country eSIMs if you want full-speed data, separate allowances so a heavy week in Seoul does not eat your Tokyo budget, and the lower price per gigabyte.
Does my phone support two eSIMs at once?
Most recent phones can store both eSIMs at the same time, but only one mobile data connection runs at a time, so you switch between them. According to Apple’s official guidance, iPhone 13 and later models can store more than one eSIM and keep two eSIMs active, though the phone uses one cellular data network at a time (Apple Support, accessed June 2026). That single-data-network limit is exactly why the on-arrival switch exists: your Korea eSIM and Japan eSIM both live on the phone, and you tell the phone which one to use for data in each country.
Devices that handle this well
In practice, any eSIM-capable, carrier-unlocked phone works: iPhone XS and newer, recent Google Pixel models, and Samsung Galaxy S20 and newer, the range Kimchi Mobile lists for its eSIMs. A phone locked to a home carrier may refuse to install the profile, so confirm it is unlocked before you buy. Older handsets without eSIM support need a physical travel SIM.
What “data-only” means for both legs
Both eSIMs give you mobile data and nothing else: no Korean or Japanese number, and neither line receives SMS codes tied to a local number. For travel that is enough. Maps, translation, ride-hailing, and messaging over data (KakaoTalk, LINE, WhatsApp, iMessage) all run on data. A real Korean 010 number for banking or long-term services is a separate, longer process, covered below.
How do I switch the eSIM on arrival in each country?
You switch in your phone’s cellular settings, and it takes well under a minute. Install both eSIMs over Wi-Fi before you leave home, label them clearly (“Korea” and “Japan”), then turn on the right line when you land. Here is the sequence.
Before you fly
- Install both eSIM QR codes while you are on Wi-Fi at home. Kimchi Mobile delivers each eSIM as a QR code by email, and the validity period starts when you activate, not when you install, so you can set them up early without burning days.
- Rename each line so you can tell them apart: in iOS, Settings > Cellular > tap the plan > Cellular Plan Label.
- Keep both lines turned off (or set to off for data) until you arrive, so neither one activates prematurely.
When you land in Korea
- Open Settings > Cellular (or Mobile Data on some regions).
- Turn the Korea eSIM line on and set it as the line for Cellular Data; turn the Japan line off for data.
- Enable Data Roaming for that eSIM if prompted, because travel eSIMs need it on to register, even though you are not paying roaming fees (Apple iPhone User Guide, accessed June 2026).
- It connects to KT within a couple of minutes of powering on at Incheon or Gimhae.
When you land in Japan
- Open Settings > Cellular again.
- Set the Japan eSIM as the line for Cellular Data and turn the Korea line’s data off.
- Enable Data Roaming on the Japan line; it registers on a local Japanese network shortly after you power on at the airport.
Android phones follow the same logic under Settings > Network & internet > SIMs, where you pick which downloaded SIM handles mobile data. The labels and exact wording differ by manufacturer, but the choice is the same: one line for data at a time.
How much data do I need for Korea and Japan?
For a one-to-two-week trip, plan on roughly 1 GB per day of moderate use per country, then size each eSIM to its leg. Maps, messaging, social, and the odd video stream add up faster than people expect in an unfamiliar city. Sizing each eSIM to its own leg is the main reason two country eSIMs beat a shared regional pool: a data-heavy week in Seoul will not leave you throttled in Kyoto.
| Your use | Per day | 7-day leg | Suggested eSIM size |
|---|---|---|---|
| Light (maps, chat, occasional browsing) | ~0.5 GB | ~3.5 GB | 5 GB |
| Moderate (social, photos, some video) | ~1 GB | ~7 GB | 10 GB |
| Heavy (streaming, hotspot, video calls) | ~2 GB+ | ~14 GB+ | 20 GB |
Kimchi Mobile’s Korea eSIM comes in 5 GB, 10 GB, and 20 GB tiers (priced from $9.99 as of June 2026), and the Japan eSIM in 5 GB and 10 GB. If you slightly overshoot in Korea, the Korea plan keeps you connected at a reduced speed for essentials like maps and messaging after the full-speed allowance is used, rather than cutting you off.
Will either eSIM give me a Korean phone number?
No. Both the Korea eSIM and the Japan eSIM are data-only, and a Korea travel eSIM never carries a Korean number. On arrival, any foreign visitor gets mobile data, not a phone number. A real Korean 010 number is issued only after you hold your physical Alien Registration Card (ARC / 외국인등록증) and convert to a KT postpaid (후불) plan, and that path is open only to long-stay residents on a qualifying visa: F-series; E-1, E-2, E-5, E-7, and E-9; and long-stay D-series such as D-2 students and D-10.
The rules here are strict. Foreigners staying longer than 90 days generally must register and obtain an ARC, and the physical card itself usually takes about two to three weeks to be issued after you apply, often longer (see Korea’s official immigration portal, HiKorea, run by the Ministry of Justice). The registration-fact certificate (외국인등록사실확인서) is not accepted for activating a number yet; only the physical ARC card works. Short-term travelers, tourists, and visa-waiver visitors cannot get a Korean number at all, which is precisely why a data eSIM is the right tool for a Korea-plus-Japan trip. If you are moving to Korea long-term and want the full picture, see our guide on how to get a Korean phone number as a foreigner.
FAQ
Can I use one eSIM for both Korea and Japan?
Yes, a regional eSIM covering both countries exists and works, but on a two-country trip a dedicated Korea eSIM and a dedicated Japan eSIM usually give you faster local-network speeds, separate data allowances, and a lower price per gigabyte. The only extra step is switching the active line in your settings when you land in each country.
Do I need to switch eSIMs when I cross from Korea to Japan?
Yes, if you carry two country eSIMs. When you land in Japan, open your phone’s cellular settings, set the Japan eSIM as the line for mobile data, and turn the Korea line’s data off. It takes under a minute, and the Japan line registers on a local network shortly after you power on.
Will a Korea or Japan travel eSIM give me a phone number?
No. Both are data-only, so you get mobile data but no Korean or Japanese phone number and cannot receive SMS codes tied to a local number. Apps that work over data, such as KakaoTalk, LINE, WhatsApp, maps, and ride-hailing, all function normally.
What phones support two eSIMs for a Korea and Japan trip?
Most recent unlocked phones do. Apple states that iPhone 13 and later can store and activate two eSIMs, using one for data at a time; recent Google Pixel and Samsung Galaxy S20-and-newer models work the same way. The phone must be carrier-unlocked for the eSIM profiles to install.
When do I install the eSIMs?
Install both over Wi-Fi before you fly. Kimchi Mobile sends each eSIM as a QR code by email, and the validity period starts when you activate the line, not when you install it, so setting them up early does not waste days.
Do I need to turn on data roaming for a travel eSIM?
Usually yes. Travel data eSIMs need Data Roaming enabled on that line to register on the local network, even though you are not paying any roaming charge. You enable it per line in your phone’s cellular settings.
Can a tourist get a Korean phone number with a SIM?
No. A real Korean 010 number requires a physical Alien Registration Card and a qualifying long-stay visa, which short-term and visa-waiver visitors do not have. Travelers use a data-only eSIM instead, and that covers everything a trip needs.
The simplest setup for a Korea + Japan trip
For a combined itinerary, buy one Korea eSIM and one Japan eSIM, install both at home, and flip the active line in your settings as you land in each country. You keep full-speed local data, a separate allowance for each leg, and one less thing to figure out at the airport. Grab the Korea prepaid eSIM and the Japan prepaid eSIM, or compare every plan in the Kimchi Mobile shop. If you are unsure whether your visa or device qualifies for anything beyond data, ask before you buy and we will point you the right way.