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M1 roaming Japan: Charges and activation
Discover M1 roaming Japan plans, data rates, and how to activate roaming for prepaid and postpaid users before you travel.
Using your M1 roaming Japan is possible, but it’s not always straightforward. From roaming packs to pay-per-use rates, knowing your options ahead of time can help you avoid unexpected charges abroad.
This guide breaks down how M1 data roaming in Japan works for prepaid and postpaid users, including current pricing, supported networks, and activation steps.
We’ll also cover an M1 alternative worth considering: the Holafly eSIM for Japan for unlimited, hassle-free data while travelling.
Activate when needed
Buy your eSIM for Japan ahead of time to get connected as soon as you arrive.
Can you use M1 data roaming in Japan?
Yes, M1 roaming in Japan is fully supported for both prepaid and postpaid users. With the right add-on or roaming pass, you can use your Singapore mobile number to access calls, texts, and high-speed data throughout Japan.
M1 partners with top-tier Japanese networks like NTT Docomo, SoftBank, and KDDI, offering reliable coverage for calls and mobile internet in Japan, especially in major cities and transport hubs.
Before your trip, be sure to activate the appropriate roaming plan to avoid pay-per-use charges and ensure uninterrupted service on arrival.
M1 Japan roaming plans and charges
Whether you’re a prepaid or postpaid user, M1 eSIM offers several ways to stay connected in Japan, from data add-ons to daily roaming passes.
But costs can vary significantly depending on how long you’re staying and whether you activate a plan in advance.
Here, we’ll break down M1 Japan roaming options, including prepaid data packs, pay-per-use rates, and monthly data passports for postpaid users.
M1 prepaid roaming and data packs for Japan
If you’re using an M1 prepaid SIM, you can roam in Japan by purchasing a roaming add-on pack through the M1 Prepaid App or portal.
The only option currently available is 2GB Data + 10 minutes of calls for SGD $28 for 10 days. (Valid in 17 countries, including Japan)
Just make sure to activate it before you travel, as usage outside the pack will fall under pay-per-use rates.
M1 prepaid pay-per-use rate in Japan
If you don’t activate an M1 roaming Japan pack, your prepaid SIM will default to pay-per-use roaming rates in Japan, often the most expensive option.
Currently, data is charged at SGD $0.03 per KB, which means just 1MB of usage could cost over SGD $30. Simple actions like opening Google Maps or sending a photo on WhatsApp could quickly drain your balance.
To avoid unexpected roaming charges, it’s strongly recommended to activate a roaming pack before you fly.
M1 postpaid roaming Data Passport for Japan
For postpaid users, M1 offers several roaming add-ons that provide better value and wider coverage compared to pay-per-use rates.
These plans allow you to use your existing local data bundle while abroad. Just be aware that usage beyond your data limit may incur additional charges of SGD $12.22/GB.
Here are the main M1 roaming Japan options for postpaid users:
| Plan | Coverage | Price (SGD) | Validity |
|---|---|---|---|
| Daily Passport | Japan and 70+ countries | $3.95 | 1 day |
| ASEAN Data Passport | 9 ASEAN countries (incl. Japan) | $35 | 1 month |
| Asia Data Passport | 17 countries across Asia | $65 | 1 month |
M1 postpaid pay-as-you-go roaming in Japan
If you’re a postpaid user and don’t activate an M1 roaming plan for Japan before your trip, your data usage in Japan will be billed at SGD $0.02 per MB, plus an additional 20% surcharge.
While this is lower than prepaid rates, costs can still add up quickly — especially for high-data activities like navigation, social media, or video calls. Even background app activity could result in unexpected charges.
To prevent this, it’s best to estimate your data usage to choose a plan for your needs and activate a Daily or Monthly Data Passport before departure.
How to activate M1 roaming in Japan
Activating M1 roaming in Japan is straightforward, but it’s best to do it before leaving Singapore to avoid any service disruptions overseas.
- Postpaid users: Activate roaming and select your add-on via the My M1+ App.
- Prepaid users: Use the M1 Prepaid App, log in to the Prepaid Portal, or dial #100*8*1# directly on your phone.
Once activated, make sure that data roaming is enabled in your phone settings.
Stay connected in Japan with Holafly eSIM
Looking for a simpler alternative to M1 roaming? The Holafly’s Japan eSIM offers unlimited data, fast activation, and no surprise charges. It offers two flexible eSIM plan types:
- Daily eSIM Plan: Starting at SGD $8.00 per day, ideal for short-term trips or stopovers.
- Monthly Holafly Plans: From USD $49.90 per month, great for remote workers, students, or extended stays.
Both options include:
- Unlimited data at 5G speeds
- Coverage across Japan and 170+ global destinations
- 24/7 multilingual customer support
- Hotspot sharing and tethering
- Instant activation via QR code with no SIM swap needed
Forget juggling roaming settings, Holafly’s international eSIM makes staying connected in Japan effortless and cost‑effective.
Get connected quicker
Buy, set up, and activate a Holafly eSIM for Japan in no more than a few of minutes.
Disclaimer: The data in this article is accurate as of October 22nd, 2025, and is subject to change.
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Formerly a travel journalist turned marketing copywriter, I found my way back to the travel world with Holafly—my dream company that made remote work possible. My motto? “Dream big and make it happen.” I’m passionate about writing, exploring the world, and staying active through walking, running, swimming, and hiking. I also love learning, reflecting, and connecting with inspiring minds.
