Best eSIM for Japan: A UK Traveller's Guide

Japan is a trip where your phone does a lot of work. You will use it for train times, maps, translation and finding that tiny restaurant down a side street in Kyoto. The right Japan eSIM gets you online without a pocket wifi device to carry or return.

This guide covers how to choose the best eSIM for Japan as a UK traveller, from networks to how much data you need. You can see current plans on our Japan eSIM page.

1. Why Use an eSIM in Japan?

Most UK visitors have three options: roam on their UK plan, rent a pocket wifi or use an eSIM.

• Roaming: simple, but daily costs add up across a one or two week trip
• Pocket wifi: shareable, but it is another device to collect, charge and return
• eSIM: it lives on your phone, so there is nothing to carry or send back

An eSIM is delivered by email, so you can sort your data before you leave home and be online when you land at Haneda, Narita or Kansai.

2. Which Japanese Networks Will You Be On?

This is the part worth checking, because Japan plans differ more than most. Across our range you will see four networks: NTT docomo, KDDI/au, SoftBank and Rakuten Mobile.

• Standard fixed-data plans: can connect to NTT docomo, KDDI/au, SoftBank and Rakuten Mobile
• Plans labelled IIJ: use NTT docomo
• Most unlimited plans: use KDDI/au and SoftBank
• 21-day unlimited: also includes NTT docomo

All offer 4G and 5G where available. Coverage is generally very good in cities and along main rail routes, while rural areas and mountains can be patchier.

Only some of our Japan plans support TikTok and ChatGPT. If you need them, choose a plan with them in its name.

3. How Much Does a Japan eSIM Cost?

Prices can change, so check the plan page for today's figure. As a guide:

• 3GB for 30 days: under £6
• 5GB for 30 days: under £8
• 10GB for 30 days: under £12
• 20GB for 30 days: under £18
• 7-day unlimited: under £18
• 14-day unlimited: under £31
• 30-day unlimited: under £49

All prices are in pounds, so there are no currency conversion fees on UK cards.

4. Unlimited or Fixed Data?

• One week, mostly maps and messaging: 5GB
• Two weeks across several cities: 10GB or 20GB
• Heavy video, or working as you travel: unlimited

Our Japan unlimited plans give you 1GB of high-speed data each day. After that you stay connected at a lower speed until the next day. For most travellers, that works well for maps and messaging later in the day.

Not sure how much you need? Try our travel data calculator.

5. Using Your eSIM Around Japan

Your data helps most on the move. It keeps route planners working between Tokyo, Kyoto and Osaka, lets you check platforms on the shinkansen and makes translation apps useful in restaurants. If you are travelling with family, plans that allow hotspot can share data with another device.

6. Visiting South Korea or China Too?

If Japan is one stop on a longer trip, you may not need a separate eSIM for each country. We offer Japan and South Korea plans, plus a China mainland, Japan and South Korea option. Longer routes can use an Asia plan. Check the coverage list before you buy.

7. Setting Up Before You Fly

• Check your phone on our device compatibility page and make sure it is network-unlocked
• Buy online and receive your QR code by email
• Install your eSIM at home on wifi before you travel
• When you land, switch to your eSIM for data
• Keep your UK SIM on for calls and bank texts

Our plans are data only, so they do not include a Japanese phone number. Messaging apps keep working over data.

8. Who Should Use a Japan Travel eSIM?

• First-time visitors relying on maps and translation
• Couples and families on a city and culture trip
• Travellers who do not want to rent or return a device
• Anyone trying to avoid daily roaming charges

Planning your trip? Read our Japan travel 2026 guide as well.

Final Thoughts

For most UK travellers, the best eSIM for Japan is a 5GB to 20GB plan that matches your trip, or an unlimited plan if you use a lot of video. Check the network on the plan card, install at home and you will be ready before you board. Browse our Japan eSIM plans to find yours.