How to Switch from au to Rakuten Mobile SIM Unlock Guide [2026 Guide]

Thinking about switching your Japanese mobile plan from au to Rakuten Mobile? You’re not alone. With Rakuten Mobile’s flat-rate unlimited data plan at just ¥3,278/month (tax included), many foreign residents in Japan are making the move — and with an employee referral campaign offering up to 14,000 points, the timing has never been better.

This step-by-step guide walks you through everything: SIM unlocking your au device, issuing your MNP reservation number, and completing your Rakuten Mobile application — with tips tailored specifically for foreign residents navigating Japan’s telecom system.

Why Switch from au to Rakuten Mobile?

Au’s plans can run anywhere from ¥5,000 to ¥9,000+ per month depending on data usage. Rakuten Mobile’s Rakuten最強プラン (Saikyo Plan) covers unlimited data nationwide for a single flat rate of ¥3,278/month — no tier pricing, no surprise overages.

For foreigners in Japan, Rakuten Mobile also offers a relatively straightforward application process and solid English-language support resources. Pair that with the current employee referral campaign bonus, and the financial case for switching becomes hard to ignore.

Quick point comparison:

Normal MNP campaign: 13,000 points

Via employee referral link: 14,000 points (1,000pt extra)

New signup via referral: 11,000 points

For a deep dive on the full referral campaign structure, see: Rakuten Mobile Employee Referral Campaign: Get Up to 14,000 Points — Complete Guide for Foreign Residents in Japan [2026 Guide]

Step 1: SIM Unlock Your au Device

Before you can use a Rakuten Mobile SIM in your current au smartphone, you need to SIM unlock it. Au-locked phones will not work on another carrier’s network without this step.

How to SIM Unlock an au Phone

Option A: Online (Recommended)

Visit au’s official website and log in to your My au account.
Navigate to “SIM Lock Unlock” (SIMロック解除) under device settings.
Enter your IMEI number (dial *#06# on your phone to find it).
Follow the on-screen instructions. The unlock is typically processed immediately.

Option B: At an au Store

Bring your device and ID (residence card/passport) to any au shop.
Note: A handling fee of ¥3,300 applies for in-store unlocks (online is free).

SIM Unlock Eligibility

The device must have been purchased from au.
Some older models or installment-plan devices may have conditions. Check au’s eligibility list on their site.
Once unlocked, your phone will work with any compatible Japanese or international SIM.

Tip for foreign residents: If your phone was purchased outside Japan (e.g., an iPhone or Samsung bought internationally), it may already be SIM-unlocked. You can skip this step and go straight to the MNP process.

Step 2: Get Your MNP Reservation Number from au

MNP (Mobile Number Portability) lets you keep your existing phone number when switching carriers. You’ll need a reservation number from au before applying to Rakuten Mobile.

How to Issue an MNP Reservation Number

Option A: Via My au App or Website

Log in to My au.
Go to “手続き” (Procedures) → “MNP予約番号発行” (Issue MNP Reservation Number).
The number will be displayed and also sent via SMS/email.

Option B: Call au Customer Support

Dial 0077-7-111 (au MNP desk, toll-free)
Hours: 9:00 AM – 8:00 PM daily
English support may be limited — consider using a translation app or asking a Japanese-speaking friend if needed.

Important MNP Notes

The MNP reservation number is valid for 15 days from issue date. Apply to Rakuten Mobile before it expires.
Au may try to retain you with counter-offers during this step — politely decline if you’ve already decided to switch.
No cancellation fee is required for MNP transfers at au (as of 2024 regulations).

Step 3: Prepare Your Documents

Rakuten Mobile requires identity verification. As a foreign resident, you’ll typically need:

Residence card (在留カード / Zairyu Card) — most commonly accepted
Passport (sometimes required alongside the residence card)
A Japanese bank account or credit card for payment setup
Your MNP reservation number (from Step 2)

Make sure your residence card is current and not expired. Rakuten Mobile’s online application supports uploading photos of these documents directly through your smartphone camera.

Step 4: Apply via the Employee Referral Link

This is the step where many people leave money on the table. If you apply through the standard Rakuten Mobile website without a referral link, you’ll receive up to 13,000 points via the normal MNP campaign. But if you apply through an employee referral link, you get 14,000 points — that’s 1,000 extra points, just for using the right URL.

What Makes the Employee Referral Campaign Special

Beyond the extra 1,000 points, the employee referral campaign has some exclusive advantages over the normal friend referral program:

✅ Re-contracts are eligible (switching back after a previous Rakuten Mobile contract)
✅ 2nd and additional lines are eligible (adding lines for family members counts too)
❌ These two cases are not covered by the standard friend referral program

How to Apply

Click the employee referral link first: https://r10.to/henTIE
This will direct you to Rakuten Mobile’s application page with the referral tracked.
Log in to your Rakuten account (or create one if you don’t have one).
Choose your plan (Rakuten最強プラン, ¥3,278/month unlimited).
Select SIM card or eSIM, enter your MNP reservation number, and complete identity verification.
Set up payment and confirm your order.

Login rescue rule: Even if you forgot to click the referral link before applying, you can still qualify — as long as you log in to Rakuten Mobile’s My Page via the referral link within 7 days of your application date.

Step 5: Complete Activation and Claim Your Points

For Physical SIM Cards

Your SIM card will arrive by mail within a few business days. Follow the included instructions to activate it. Once active, insert it into your now-unlocked au device.

For eSIM

eSIM setup can often be completed the same day. After your application is approved, you’ll receive a QR code to scan and configure the eSIM directly on your phone. For a detailed walkthrough, check out: Rakuten Mobile Activation Same Day: Quickest Process for SIM & eSIM — Complete Guide for Foreign Residents in Japan [2026 Guide]

Making Your First Call (Required for Points)

⚠️ Important for applications from March 2, 2026 onward: To receive your referral points, you must make a call of 10 seconds or more using the Rakuten Link app. Simply activating your SIM is not enough.

Data-only SIM holders are not eligible for the point campaign.

Download the Rakuten Link app (free), and make any call — even to a service number or a short test call with a friend — that lasts at least 10 seconds. Do this early so you don’t forget.

Understanding Your Point Payout

Once you’ve completed the steps above, here’s how your points will arrive:

Condition	Points
MNP via employee referral	14,000 points
New signup via employee referral	11,000 points
MNP via normal campaign (no referral)	13,000 points

Payout schedule: Points are distributed in 3 installments, beginning 4 months after the month you first logged in via the referral link.

⚠️ Critical note about point type: The points awarded through this campaign are “limited-period points” (期間限定ポイント), NOT regular Rakuten points. Limited-period points have an earlier expiration date than standard points. Use them promptly — check your Rakuten point wallet regularly and spend them before they expire.

Rakuten points can be used across a huge ecosystem: Rakuten Ichiba shopping, Rakuten Pay (accepted at many convenience stores and restaurants), and more — so spending them shouldn’t be difficult.

Rakuten Mobile Coverage: Is It Good Enough?

One common concern among foreign residents is whether Rakuten Mobile’s network is reliable enough after leaving a major carrier like au. The honest answer is: it depends on where you live and work.

Rakuten Mobile has been aggressively expanding its own 4G/5G infrastructure and also has a roaming agreement with au for areas not yet covered. For most urban and suburban areas — Tokyo, Osaka, Nagoya, Fukuoka, Sapporo — coverage is quite solid.

For the latest on network expansion: Rakuten Mobile Coverage Expansion 2026: Is the 99.9% Population Coverage Goal Finally Here? [2026 Guide]

If you’re in a rural area or frequently travel to remote regions, it’s worth checking Rakuten’s coverage map for your specific locations before committing.

Quick Checklist Before You Switch

SIM unlock your au device (online for free, or in-store for ¥3,300)
Issue MNP reservation number from au (valid 15 days)
Prepare residence card, passport, and payment method
Click the referral link before applying
Choose SIM card or eSIM on the Rakuten Mobile application page
Complete identity verification and payment setup
Activate your SIM/eSIM
Download Rakuten Link and make a call of 10+ seconds
Monitor your Rakuten point wallet — limited-period points expire sooner

Final Thoughts

Switching from au to Rakuten Mobile is a straightforward process once you know the steps — and for foreign residents in Japan looking to cut their monthly phone bill significantly, it’s one of the most impactful financial decisions you can make. At ¥3,278/month for truly unlimited data, the savings compared to most au plans add up quickly.

Add in 14,000 limited-period points via the employee referral campaign (an extra ¥14,000 worth of value, though remember to use them before they expire), and the switch pays for itself almost immediately.

If you’re ready to get started, use the employee referral link below to make sure you receive the maximum point bonus — including coverage for re-contracts and additional lines that the standard campaign doesn’t offer:

👉 Apply via Employee Referral Link — Get 14,000 Points for MNP

Take your time going through each step, and don’t hesitate to reach out to Rakuten Mobile’s support if anything is unclear during the application process. Good luck with your switch!