Yes, you can use this service if the following conditions are met:

✅ Your smartphone is connected to Wi-Fi
✅ The Wi-Fi Calling function is enabled
✅ You are using a supported device (iPhone / Android)
✅ Your SIM card remains active (not suspended or cancelled)

💰 Charges (Important)
Wi-Fi Calling is treated as if you are using the service in Taiwan.

📞 Making calls
・Calling a Taiwan number → Taiwan domestic call charges
・Calling a Taiwan mobile number → Taiwan domestic rates
・Calling overseas (e.g., Japan) → International call charges

👉 No international roaming charges will apply

📲 Receiving calls
・Receiving calls from Taiwan → Free (same as receiving calls in Taiwan)

🌟 Benefits
・Good call quality when the Wi-Fi connection is stable
・You can make and receive calls without enabling international roaming