Rakuten Mobile No Signal & Connection Issues: Complete Troubleshooting + Coverage Check Guide for Foreign Residents in Japan [2026 Guide]

If you’ve recently switched to Rakuten Mobile — or you’re thinking about it — you may have heard concerns about signal quality or coverage gaps. For foreign residents in Japan, dealing with a dropped connection when you don’t speak fluent Japanese can feel especially stressful. This guide walks you through the most common Rakuten Mobile signal and connection problems in 2026, how to troubleshoot them step by step, and how to verify coverage before you commit to switching.

Why Signal Issues Happen on Rakuten Mobile (and Who Is Most Affected)

Rakuten Mobile runs on its own independent network (Band 3/Band 28) combined with au’s partner network for areas where Rakuten’s own towers haven’t yet been deployed. This “hybrid” setup works well in major urban areas — Tokyo, Osaka, Nagoya, Sapporo, Fukuoka — but coverage can still be thinner in:

Rural areas and mountainous regions
Underground spaces (subway stations, basements of older buildings)
Certain indoor locations with thick concrete walls
Islands and remote coastal areas

For foreign residents who tend to live in city centers, Rakuten Mobile’s coverage is generally quite solid. However, if you frequently travel outside major urban corridors for work or leisure, it’s worth doing a proper coverage check before switching.

Step 1: Check the Coverage Map Before Anything Else

Before assuming there’s a device problem, always verify that your specific location is supposed to have coverage. Rakuten Mobile’s official coverage map is updated regularly and lets you zoom into street-level detail.

How to check:

Visit the Rakuten Mobile website and search for “エリア” (area/coverage)
Enter your home address, workplace, or any frequent location
Pay attention to whether it shows “Rakuten自社エリア” (Rakuten’s own network) or “au partner area” — both provide connectivity, but the au partner area has some data limitations depending on your usage

Key tip for foreign residents: Even if your neighborhood shows as covered, check your commute route, your workplace building, and any regular spots like a favorite restaurant or gym. Indoor penetration can vary significantly.

Step 2: Basic Troubleshooting — Try These First

If you’re already a Rakuten Mobile subscriber and experiencing no signal or weak connection, work through these basic steps before contacting support:

Restart Your Phone

This sounds obvious, but a surprising number of connectivity issues resolve themselves after a full power cycle. Hold the power button, shut down completely, wait 30 seconds, and restart.

Toggle Airplane Mode On and Off

This forces your phone to re-register with the nearest cell tower. Turn airplane mode on, wait 10 seconds, then turn it off. This often resolves temporary signal drops.

Check Your APN Settings

For foreign residents using phones purchased outside Japan, incorrect APN (Access Point Name) settings are a very common cause of data connectivity problems — even when voice calls work fine.

Rakuten Mobile’s correct APN settings are:

APN: rakuten.jp
Username: (leave blank)
Password: (leave blank)
Authentication type: None

You can find these under Settings → Mobile Data → APN (the exact path varies by device model).

Confirm Your SIM Card Is Properly Seated

If you’ve recently inserted a new SIM or had your phone bumped or dropped, the SIM may have shifted slightly. Power off, remove the SIM tray, reseat the card firmly, and power back on.

Check for Software or Carrier Settings Updates

Go to your phone’s settings and check for any pending system or carrier updates. Outdated carrier settings can cause compatibility issues, particularly on iPhones.

Step 3: Band Compatibility — Does Your Phone Actually Support Rakuten’s Network?

This is one of the most overlooked issues for foreign residents in Japan. Rakuten Mobile primarily uses Band 3 (1800 MHz) for its own network and Band 18/26 for the au partner network. If your phone — particularly one purchased overseas — doesn’t support these bands, you may experience poor signal even in covered areas.

How to check:

Search your phone’s model number + “frequency bands” or “対応バンド”
Confirm it supports Band 3 for Rakuten’s main network
Band 28 (700 MHz) is also used by Rakuten and helps with indoor coverage

iPhones purchased after iPhone 12 are generally fully compatible. Many newer Android flagships from Samsung, Google Pixel, and Sony are also compatible, but mid-range and budget phones from less common brands may have limited band support.

If your phone doesn’t support the required bands, no amount of troubleshooting will fully fix your signal issues — you may need to consider a compatible device.

Step 4: The Rakuten Link App and Your Connection

If your data is working but calls are dropping or failing, check the Rakuten Link app. Rakuten Mobile routes calls and SMS through this app, and it requires a stable internet connection to function properly.

One important note for 2026: for applications made from March 2, 2026 onward, you must make at least one call of 10 seconds or more via the Rakuten Link app to be eligible for point rewards. This applies to anyone using a referral campaign. Data-only SIM plans are not eligible for these point bonuses. So if you’re switching specifically to earn points, make sure you actually use Rakuten Link for a real call after activation.

Common Rakuten Link fixes:

Make sure the app has permission to use the microphone and make calls
Log out of the app and log back in with your Rakuten ID
Uninstall and reinstall the app if calls consistently fail
Ensure Rakuten Link is not restricted by battery optimization settings (especially common on Android)

Step 5: Indoor and Underground Signal Problems

Poor indoor signal is perhaps the most frequently reported complaint about Rakuten Mobile, and it’s a real consideration. Here’s how to manage it:

Use Wi-Fi Calling or Wi-Fi Data

When you’re at home or in the office, connect to Wi-Fi. Rakuten Mobile’s plan includes unlimited data, but if your signal is weak indoors, using Wi-Fi for data-heavy tasks makes sense. Rakuten Link also works over Wi-Fi.

Check Partner Network Roaming Settings

In your phone’s mobile network settings, make sure “roaming” or “partner network” is enabled. Without this, you may not be able to connect to au’s partner network in areas where Rakuten’s own signal is unavailable.

On iPhones: Settings → Mobile Data → Mobile Data Options → Data Roaming (enable this) On Android: Settings → Mobile Network → Roaming (enable this)

Wi-Fi Calling

Some phone models support Wi-Fi calling natively. Enabling this allows calls to be placed over Wi-Fi when cellular signal is weak — useful for home use if your apartment has limited indoor coverage.

Step 6: When to Contact Rakuten Mobile Support

If you’ve worked through all the above and still have persistent issues, it may be a genuine network problem in your area, or a fault with your specific SIM card.

Rakuten Mobile support options:

Chat support (available in the My Rakuten Mobile app) — this is often the fastest option and doesn’t require speaking Japanese
Web support via the Rakuten Mobile website
Physical stores (Rakuten Mobile Shops) — staff at many locations can help with SIM replacement if yours is faulty

For foreign residents who are not confident in Japanese, chat support tends to be more manageable than phone support, as you can use a translation app alongside the conversation.

Is Rakuten Mobile Still Worth It in 2026?

Despite the coverage caveats, Rakuten Mobile remains one of the most cost-effective unlimited data plans available in Japan. At ¥3,278 per month (tax included) for truly unlimited data with no speed throttling, it significantly undercuts the major carriers (NTT Docomo, au, SoftBank) for heavy data users.

For foreign residents especially, the math is compelling: one flat price, no complex tier system, and no surprise overage fees. If you primarily live and work in a major city and do most of your mobile usage in covered areas, the coverage limitations are unlikely to affect your daily life significantly.

You might also find this comparison helpful: povo2.0 vs Rakuten Mobile: Price, Top-Up, Points & Which Is Better for Foreign Residents in Japan [2026 Guide] — it breaks down exactly how Rakuten stacks up against a popular alternative for data-focused users.

If you’ve done your coverage check, confirmed your phone is compatible, and decided Rakuten Mobile is the right fit, there’s a smart way to sign up that puts extra points in your pocket.

Rakuten Mobile currently runs an employee referral campaign that offers more points than the standard sign-up bonus:

MNP (switching from another carrier): 14,000 points via referral (vs. 13,000 points on the normal campaign — that’s 1,000 extra points just for using a referral link)
New number signup: 11,000 points via referral

Important details to know:

Points are paid out in 3 installments starting 4 months after your referral login month — so plan accordingly
The points awarded are limited-period points, not regular Rakuten Points — they expire sooner than standard points, so use them promptly after each installment arrives
You can apply for up to 5 lines per person
Re-contracts and second/additional lines are also eligible — this is an employee referral exclusive benefit not available through regular friend referral campaigns
If you forget to log in via the referral URL at the time of application, you have a 7-day window to log in via the referral URL and still qualify

For a detailed walkthrough of the entire application process as a foreign resident, including document requirements and step-by-step signup instructions, check out: Rakuten Mobile Employee Referral 2026: Complete Guide for Foreigners in Japan — Get Up to 14,000 Points

Final Thoughts

Signal issues on Rakuten Mobile are real but manageable — and for most foreign residents living in Japan’s major cities, they’re unlikely to be a dealbreaker. The key is doing your homework upfront: check the coverage map for your specific locations, confirm your phone supports the necessary frequency bands, and configure your APN and roaming settings correctly.

If you’ve worked through this guide and Rakuten Mobile looks like a good fit, applying through a referral link is simply the better deal — you get 1,000 more points than the standard campaign for MNP transfers, with no additional steps or conditions required on your end.

👉 Apply via referral link here (14,000 points for MNP / 11,000 points for new signup): https://r10.to/henTIE

Remember: make at least one Rakuten Link call of 10 seconds or more after activation to ensure your points are awarded, and use your limited-period points before they expire. Good luck with your switch!