FAQ Category International Roaming & Authentication

Can I Use JB Voice SIM in Hong Kong?

🅰️ Yes!

JB Voice SIM uses docomo’s international roaming service, so voice calls and SMS may be available while you’re in Hong Kong.

📶 The following mobile operators in Hong Kong may support VoLTE roaming:

  • CMHK (China Mobile Hong Kong)
  • CSL
  • 3 Hong Kong (Three)

⚠️ Actual availability may vary depending on several factors, including:

  • Your phone model
  • Whether VoLTE is supported and enabled on your device
  • The local mobile operator’s network conditions

We recommend confirming that your device supports VoLTE roaming before your trip for the best experience.

Please note that network environments may change over time, and actual connectivity depends on the services provided by the local mobile operator.

How Can I Check Which Mobile Network I’m Using While Roaming?

🅰️ If your phone connects only to a GSM (2G) network while roaming, voice calls and mobile data may not work properly.

📶 Please check the current network type on your device.

✅ LTE / 4G / 5G — Normal service is available.
⚠️ GSM (2G) — Some countries have discontinued 2G service, which may affect voice calls or mobile data.

🍎 iPhone

Open the Phone app and dial *3001#12345#* to check your current network type.

💡 Field Test Mode is a built-in iPhone feature and does not incur any additional charges.

🤖 Android

Check the status bar at the top of your screen. If you see 4G, LTE, or 5G, your device is connected to a supported network.

Will I Be Charged for Receiving Lawson Ticket (ローソンチケット) Verification Calls Overseas?

🅰️ Yes, charges may apply.
If you receive a Lawson Ticket verification call outside Japan, international call charges may be incurred.

📞 Fee Information
  • Taiwan / Hong Kong / Macau: approximately JPY 174 per minute
    (Actual charges depend on your mobile carrier.)
  • Receiving the call within Japan: No charge
⏱️ Verification Call Duration
  • The call usually lasts only a few seconds to several tens of seconds and normally does not exceed 1 minute.
  • The verification code is provided through a Japanese voice message, so we recommend familiarizing yourself with how Japanese numbers are pronounced in advance.
📝 Registration Notes

Based on current testing, registering directly from Taiwan may sometimes fail.

A successful method that has been confirmed is to have the registration process completed with assistance from Japan, then receive the verification call in Taiwan and enter the verification code to complete the verification process.

How can I make the phone verification call for Ticket Pia (PIA)? Can it be used from overseas?

🅰️ Yes, it is possible!
Even when you are overseas (such as Taiwan), you can complete the verification by using international roaming to make a call to the Japanese phone number.

How to dial:
・Enter “+81” (Japan country code)
・Remove the first “0” from the phone number

Example:
050-1234-5678
➡️ +81 50-1234-5678

✅ When verification is successful, the call usually rings for 1–3 times and then automatically disconnects. The verification page will also proceed to the next step.

💰 Calls made from overseas to Japan may incur international roaming call charges according to your mobile carrier’s rates.

⚠️ If verification cannot be completed, please check the following:
・Make sure +81 is entered correctly
・Make sure the initial 0 has been removed from the phone number
・Confirm that your smartphone supports international calling and VoLTE functionality

How can I use the SIM card outside Japan?

🅰️ Once you receive your SIM card, you can use international roaming for voice calls and SMS while outside Japan.

📌 How to Use
✔ Simply insert the SIM card to use voice calls and SMS via international roaming.
❌ Mobile data (internet access) is not available outside Japan.

・For iPhone: Do not install a Configuration Profile.
・For Android: Do not configure the APN settings.

⚠️ Important Notes
・🛜 Turning Wi-Fi or 📶 Mobile Data on or off does not affect voice calls or SMS while roaming.
・💰 Since this SIM does not provide mobile data outside Japan, no international data roaming charges will be incurred.