Japan eSIM: Docomo with a Japanese IP, or KDDI and SoftBank?

For a trip to Japan only, there are three country plans. Japan eSIM (Docomo) and Japan eSIM (IIJ-Docomo) both use NTT Docomo and route internet traffic through Japan, so websites may see a Japanese IP location. Japan Premium eSIM uses KDDI and SoftBank, and mainly routes traffic through Singapore, so websites may see a Singapore connection. The plans also differ in when they start, how long you have to start them, and whether they can be topped up.

Compare prices for the same data and days on the Japan eSIM plans page, because they change.

The three Japan country plans side by side

These facts come from our Japan destination page and the three product pages, checked on 6 November 2026. Each plan page is the final word if anything changes.

	Japan eSIM (Docomo)	Japan eSIM (IIJ-Docomo)	Japan Premium eSIM
Networks	NTT Docomo (4G, 5G)	NTT Docomo (3G, 4G, 5G)	KDDI and SoftBank (each 4G, 5G)
Internet route (IP location)	Japan	Japan	Singapore
Plan starts	On first connection	When you install the eSIM	On first connection
Use within	30 days of purchase	60 days of purchase	90 days of purchase
Daily allowance resets	Midnight GMT+9 (day 1 can be a few hours)	Midnight GMT+9 (day 1 starts at install and can be a few hours)	Every 24 hours from activation
Top-up	Not available	Not available	Daily plans only
Hotspot	Supported	Supported	Supported
Calls and SMS	Data only	Data only	Data only

All three pages add the usual caution: the networks are set by the mobile service and can change, and coverage depends on the network in the area, your phone and other conditions. Where a page lists 5G, read that as 5G where available and 4G otherwise.

The IP row is a factual difference between the plans. The Docomo and IIJ-Docomo pages say websites may see a Japan IP location; the Premium page says websites may see your connection as coming from Singapore. None of this changes your phone’s GPS location. We do not make claims about speed or which network covers an area better. For local apps, streaming or ticket sites, our Japan page suggests IIJ-Docomo for a Japanese IP address, and Premium for KDDI or SoftBank with 5G if you want to install before you leave home.

Plans have no ID check, and your phone must support eSIM and be carrier-unlocked.

When the plan starts

• Japan eSIM (IIJ-Docomo) starts as soon as you install it, so install it just before your trip. You have 60 days from purchase.
• Japan eSIM (Docomo) starts on first connection in Japan, with 30 days from purchase to start. You can install it and turn it off while you are outside Japan.
• Japan Premium eSIM starts on first connection, with 90 days from purchase to start, and can also be installed and turned off until you land.

Do not install early on IIJ-Docomo unless you want the days to begin. Follow the instructions in your delivery email and the eSIM installation guide.

Daily data or one allowance

Plan	Daily options	After the day’s data	One-allowance options	After the allowance
Japan eSIM (Docomo)	5 GB or 30 GB a day, 1 to 30 days	Slows to 200 kbps until the daily reset	3 GB to 100 GB, 7 to 45 days	Slows to 200 kbps
Japan eSIM (IIJ-Docomo)	1, 2 or 3 GB a day, 1 to 30 days	Slows to 256 kbps until the daily reset	1 GB to 50 GB, 7 to 30 days	The connection ends
Japan Premium eSIM	500 MB to 3 GB a day, 1 to 30 days	Slows to 128 kbps until the daily reset	1 GB to 50 GB, 7 to 30 days	1 GB and 2 GB plans end the connection; 3 GB and larger slow to 128 kbps

A daily plan gives you a fresh allowance each day, and unused daily data does not roll over. A one-allowance plan gives you a single amount for the whole validity period. The slower speed after an allowance is a fair-use limit, not more full-speed data. Our fair-use worksheet explains how to compare these limits.

How much data you need depends on how you use your phone, not on the destination. Work it out with the travel eSIM data budget worksheet, then pick the shape. Daily suits days that look alike; one allowance suits uneven days. Only Premium daily plans can be topped up, so on every other Japan plan choose enough when you buy. When a top-up is available, use the top-up page.

Choose in four questions

1. Does a Japanese IP location matter? Docomo and IIJ-Docomo route through Japan; Premium routes through Singapore.
2. Which networks do you want? NTT Docomo, or KDDI and SoftBank. We do not rank them.
3. Might you need to add data mid-trip? Only Premium daily plans can be topped up.
4. When should the days start? On install (IIJ-Docomo) or on first connection (Docomo and Premium), within 60, 30 or 90 days of purchase.

Decision table

Your trip	Start with
You want a Japanese IP location and a plan that starts on install, with 60 days to start	Japan eSIM (IIJ-Docomo)
You want a Japanese IP location and a plan that starts when you connect in Japan	Japan eSIM (Docomo)
You want KDDI and SoftBank, or to top up a daily plan	Japan Premium eSIM (daily plan)
You are buying more than 30 days before the plan should start	Japan Premium eSIM (90 days) or IIJ-Docomo (60 days)
Japan with Korea, China or other Asian countries	The regional plans listed on the Japan page (China, Japan & South Korea, Asia 15, Asia 28); see one eSIM for Japan, South Korea and China

For arrival, see staying connected in Japan and the Japan arrival phone guide.

Calls, SMS and your Malaysian number

All three Japan plans are data only, with no calls or SMS. If you need your Malaysian number for calls and SMS codes, keep that line on alongside the eSIM. Data-only eSIMs: calls, SMS and WhatsApp explains the setup, and keeping your Malaysian number for bank TAC covers bank codes.

Common questions

Which Japan eSIM gives me a Japanese IP address?

Japan eSIM (Docomo) and Japan eSIM (IIJ-Docomo) route internet traffic through Japan, so websites may see a Japan IP location. Japan Premium eSIM mainly routes through Singapore. None of them changes your phone’s GPS location.

What is the difference between Japan eSIM (Docomo) and IIJ-Docomo?

Both use NTT Docomo and a Japan route. Docomo starts on first connection, with 30 days to start, and offers 5 GB or 30 GB a day or 3 GB to 100 GB in one allowance. IIJ-Docomo starts on install, with 60 days to start, and offers 1 to 3 GB a day or 1 GB to 50 GB in one allowance.

Can I top up a Japan eSIM?

Only Japan Premium eSIM daily plans can be topped up. Docomo and IIJ-Docomo cannot.

What happens when I use up my data in Japan?

On a daily plan, speed drops until the next reset: 200 kbps on Docomo, 256 kbps on IIJ-Docomo, 128 kbps on Premium. On a one-allowance plan, Docomo slows to 200 kbps, IIJ-Docomo ends the connection, and Premium ends it for 1 and 2 GB and slows to 128 kbps from 3 GB.

Does a Japan eSIM include calls or SMS?

No. All three are data only.

When should I install my Japan eSIM?

Docomo and Premium can be installed before you fly and start when they first connect in Japan. IIJ-Docomo starts as soon as you install it, so install it just before your trip.