For a trip to Japan and South Korea, one two-country eSIM is the best value: 10 GB for 30 days covering both cost $9.00 with us on 12 October 2026, and 20 GB cost $14.60. On the pages we checked, Airalo, Ubigi and Holafly sell the two countries separately or inside an Asia plan: two 10 GB country plans cost $37.00 with Airalo and $30.50 with Ubigi, and their Asia plans cost $25.00 and $42.00. For unlimited data in both countries, Airalo’s Asia week is $26.00 and Holafly’s $27.50; we do not sell one.
The usual itinerary is Tokyo, Kyoto and Osaka, then a short flight or the Busan ferry to Korea, or the same in reverse. You do not want to be buying a second eSIM at Gimhae airport, and you do not want to pay for data you will not use. Below are four providers’ own prices for both approaches, the networks our plans use, and the cases where two plans or someone else’s plan is the better buy.
Quick picks by trip
| Your trip | What to buy | Price |
|---|---|---|
| Both countries, up to two weeks, maps and messaging | South Korea and Japan, 10 GB for 30 days | $9.00 |
| Both countries, up to a month, heavier use | South Korea and Japan, 20 GB for 30 days | $14.60 |
| You tether a laptop in Japan | A Japan 10 GB plan and a Korea 10 GB plan | $14.20 |
| Also visiting mainland China | China, Korea and Japan, 12 GB for 30 days | $10.60 |
| Also visiting Taiwan, Thailand or Vietnam | Asia 12 countries, 10 GB for 30 days | $9.80 |
| Five days or less across Japan, Korea and China | Short-trip plan, 4 GB for 5 days | $5.00 |
Japan and Korea eSIM prices compared
These are the prices on each provider’s own pages on 12 October 2026, in US dollars. Where a provider has no plan for just these two countries, the row uses its Asia plan. Saily blocked our automated check with a verification page, so it is not included.
| Option | Code eSIM | Airalo | Ubigi | Holafly |
|---|---|---|---|---|
| One plan for both, 10 GB, 30 days | $9.00 (2 countries) | $25.00 (Asia, 18 countries) | $42.00 (Asia, 26 destinations) | Unlimited only |
| One plan for both, 20 GB, 30 days | $14.60 | $39.00 | Not checked | Unlimited only |
| Two country plans, 10 GB each, 30 days | $14.20 | $37.00 | $30.50 | Unlimited only |
| Unlimited in both, 7 days | Not sold | $26.00 (Asia) | Not checked | $27.50 (Asia, 16 countries) |
| Unlimited in both, 15 days | Not sold | $49.00 | Not checked | $51.50 |
| Unlimited in both, 30 days | Not sold | $73.50 | Not checked | $76.50 |
The two country plans in the third row are each provider’s 10 GB plans for 30 days. Ours are Japan at $7.00 and South Korea at $7.20; Airalo’s are $18.00 and $19.00, and Ubigi’s $16.50 and $14.00. Airalo’s unlimited plans slow to 1 Mbps after 3 GB a day. Holafly’s have no daily speed cap, but hotspot sharing is limited to 1 GB a day.
One plan or two: the cost compared
These are our prices on 12 October 2026.
| Need | One plan for both | Two country plans |
|---|---|---|
| About 10 GB in total | $9.00 for 10 GB shared | Japan 5 GB at $5.30 and Korea 5 GB at $5.00: $10.30 |
| About 20 GB in total | $14.60 for 20 GB shared | Japan 10 GB at $7.00 and Korea 10 GB at $7.20: $14.20 |
At 10 GB in total, the two-country plan is cheaper than two 5 GB plans. At 20 GB, two country plans cost 40 cents less. The two-country plan shares its data between the countries, so if you spend most of the trip in one of them, the allowance follows you. Two separate plans split it in advance, and you install two eSIMs.
Networks, hotspot and where your data exits
The plan page for each of our plans lists the local networks, the country your data exits in, and whether you can add data later. The exit location is the country that websites see you in.
| Our plan | Japan | South Korea | Data exits in | Top-up |
|---|---|---|---|---|
| South Korea and Japan | KDDI, SoftBank | SK Telecom, LG U+ | Hong Kong | Yes |
| Asia 12 countries | KDDI, SoftBank | SK Telecom, LG U+ | Singapore | No |
| Japan 10 GB (single country) | NTT Docomo | Not covered | Japan | No |
| Korea 10 GB (single country) | Not covered | SK Telecom, LG U+ | Hong Kong | Yes |
Three details matter before you buy the two-country plan:
- Hotspot in Japan. The plan page says hotspot sharing has a data limit on the KDDI network in Japan, and does not state the amount. If you plan to tether a laptop in Japan, buy the single-country Japan plan for that leg.
- When the days start. Its 30 days run from the first data connection in Japan or South Korea, not from the day you install it, and it must be started within 60 days of purchase. Our guide to when an eSIM starts counting explains the rules.
- Exit location. Its data exits in Hong Kong in both countries. The single-country Japan plan exits in Japan.
For more on the networks, see Japan eSIM: Docomo, SoftBank or KDDI and Korea eSIM: SK Telecom, KT or LG U+.
Adding mainland China
Two of our plans cover China, Japan and South Korea together, and they start differently.
| Plan | Price | Days start | Top-up |
|---|---|---|---|
| China, Korea and Japan, 12 GB for 30 days | $10.60 | On first data use | No |
| China, Korea and Japan, 7 GB for 30 days | $9.00 | When installed | Yes |
Both exit in Hong Kong. The 7 GB plan starts its 30 days when you install it, so install it a day or two before you fly, not a fortnight before. Our page on where China eSIM data exits covers the China plans one by one.
When to buy two plans, or someone else’s plan
- You stream video every day in both countries. We do not sell one unlimited plan for both. Airalo’s Asia week is $26.00 and Holafly’s $27.50. For Japan alone, our unlimited week is $19.00, with no daily speed cap; our guide to unlimited Japan plans has the details.
- You want a Japanese IP address in Japan. The single-country Japan plan exits in Japan. The two-country plan exits in Hong Kong.
- You tether a lot in Japan. The two-country plan has a hotspot limit on KDDI there.
- You need a phone number. All of these plans are data only. Our guide to phone numbers on Japan, Korea and China eSIMs explains the options.
Visiting only one of the two? Our guides to the best eSIM for Japan and the best eSIM for South Korea compare our prices with Airalo, Ubigi and Holafly in each country.
Going to Japan? Our Japan local eSIM page lists every plan on NTT Docomo and KDDI 5G, all with a Japanese IP address, and recommends one from your trip length and daily use.
Frequently asked questions
What is the best eSIM for Japan and Korea?
For most trips, one plan that covers both. On 12 October 2026, 10 GB for 30 days cost $9.00 with Code eSIM on a two-country plan, against $25.00 for Airalo’s Asia plan and $42.00 for Ubigi’s. For unlimited data in both countries, Airalo’s Asia week is $26.00 and Holafly’s $27.50.
Is there one eSIM for Japan and Korea?
Yes. Our South Korea and Japan plan covers both countries with 10 GB for 30 days at $9.00 or 20 GB at $14.60, on 12 October 2026. The plan page lists KDDI and SoftBank in Japan and SK Telecom and LG U+ in South Korea, and the data is shared between the two countries.
Is it cheaper to buy separate eSIMs for Japan and Korea?
For about 10 GB in total, no: the two-country plan cost $9.00 against $10.30 for two 5 GB plans. For about 20 GB, two country plans cost 40 cents less, at $14.20 against $14.60, but you install and switch between two eSIMs.
When should I install a Japan and Korea eSIM?
Our South Korea and Japan plan starts its 30 days at the first data connection in either country, so you can install it before you fly. Start it within 60 days of buying it. Our 7 GB plan for China, Korea and Japan is different: it starts when installed.
Does the Japan and Korea eSIM work on the ferry between Busan and Fukuoka?
It works where the ship is in range of a Japanese or Korean land network, typically near the ports. In open water, the phone may have no signal. Download maps and tickets before boarding, and expect service again as you approach port.
Can I use a hotspot with a Japan and Korea eSIM?
Yes, with one limit. Our South Korea and Japan plan lists hotspot as supported, but its plan page says sharing has a data limit on the KDDI network in Japan. The single-country Japan and Korea plans list hotspot as supported without that note.
For most Japan and Korea trips, one plan for both countries removes a step and costs about the same as two. If you tether in Japan or want a Japanese IP address there, buy the two country plans.
Last reviewed 12 October 2026; our Japan unlimited speed rule updated 23 October 2026. Airalo, Ubigi and Holafly prices, country lists and terms come from each provider’s own pages on that date, in US dollars; they change and can vary by country and promotion. Our plan networks, start rules, hotspot terms and prices come from our catalogue and product pages on the same date; product pages are authoritative. Airalo, Ubigi, Holafly, NTT Docomo, KDDI, SoftBank, SK Telecom and LG U+ are trademarks of their owners; this article is independent of them.