To use friend-search features such as ID Search or Phone Number Search on LINE, you must complete “Age Verification” to certify that you are 18 or older. However, many users—especially those who have recently switched devices or use a Budget SIM (MVNO)—frequently encounter errors such as “Verification failed” or being unable to access the carrier authentication screen.
In this article, we categorize the specific causes of LINE age verification failures into three patterns and provide a detailed recovery guide. We also highlight specific workarounds for Budget SIM users. Let’s resolve these issues so you can use the ID search feature without a hitch.
Main Causes of LINE Age Verification Failures
1. Contract and Carrier Issues (The Most Common Cause)
- Budget SIM / MVNO Compatibility: Many Budget SIM (MVNO) providers do not support the age verification systems used by major carriers, making verification technically impossible on those networks.
- Network Restrictions: Since age verification utilizes the carrier’s system, it may fail if you are connected to Wi-Fi. You often need to be on the carrier’s mobile network (4G/5G) for the authentication to work.
- Contract Mismatch: The phone number registered on LINE does not match the name or birthdate on your carrier contract, or the contract information is outdated.
- Post-Switch Delays: If you have just unlocked your SIM or switched carriers, the carrier’s system may not yet be synced with the authentication servers.
2. Connection and App Issues
- Unstable Connection: The process may time out if your internet signal drops while connecting to the authentication portal.
- Corrupted App Cache: Accumulated data (cache) within the LINE app can prevent the verification screen from loading properly.
- Outdated App Version: Using an old version of LINE that is no longer compatible with the carrier’s latest security protocols.
3. Data Entry Issues
- Date of Birth Mismatch: The birthdate set in your LINE profile differs from the one registered with your mobile carrier.
- Underage Users: If the contract holder is under 18, the ID search feature remains restricted regardless of parental consent.
Emergency Response: Steps to Resolve Verification Errors
Step 1: Basic Refresh and Update
- Force Close & Restart: Completely close the LINE app and restart your device.
- Update the App: Ensure you are using the latest version of LINE from the App Store or Google Play Store.
- Clear Cache: Go to LINE Home → Settings (gear icon) → Chats → Delete data → Select and delete “Cache”only.
Step 2: Optimize the Authentication Environment
- Turn Off Wi-Fi: Switch to mobile data (4G/5G). Many carriers require a direct mobile connection to identify your account and verify your age automatically.
- Verify Carrier Information: Log in to your carrier’s online portal (My docomo, My au, My SoftBank, etc.) and ensure your registered birthdate and name are accurate.
Step 3: Workarounds for Budget SIM Users
- Check for MVNO Support: Some providers (e.g., Mineo, IIJmio, Rakuten Mobile) have specific methods for age verification. Check your provider’s support page.
- Note for many MVNOs: If your provider does not support carrier verification, ID search will remain unavailable. Use QR codes instead.
Step 4: Final Measures
- Contact Support: If the issue persists despite having a compatible carrier and correct data, use the “LINE Contact Form” to provide details about your situation.
💡 Preventive Measures: Habits for Smooth Verification
- Sync Your Information: Always ensure that the birthdate on your LINE account matches your legal ID and mobile contract.
- Verify Early: Complete the age verification process as soon as you set up a new account or change carriers to avoid issues later.
- Prepare Alternatives: If you use a Budget SIM that doesn’t support verification, keep your QR Code or Invite URL ready to share with friends.
By following these steps, you can navigate the complexities of LINE age verification and restore your search capabilities.
