Learn how to troubleshoot Wi-Fi Calling problems. If you have an Android phone and you use the Wi-Fi Calling app, see Wi-Fi Calling troubleshooting for Android.
Can't change call forwarding, call hold, or call waiting settings
When you try to change the call forwarding or call waiting settings using Wi-Fi Calling, you may see on your screen, "Network or SIM card error." When you're actively using Wi-Fi Calling, the call forwarding and call waiting settings cannot be changed.
To resolve this issue, simply change the settings when you're not using Wi-Fi Calling, You can also use short codes to change call forwarding and call waiting settings.
Can't use call forwarding, call hold, or caller ID
If you're using Wi-Fi Calling, and the other party is using Wi-Fi Calling as well, you may notice issues with receiving incoming calls and with incoming calls not forwarding to voicemail.
To resolve this issue, visit the Phones page and select your device. Then, click the SOFTWARE UPDATE button and follow the steps to update to the latest version.
REG02, REG05, REG06, REG99 errors
This message displays when the SIM card has not received a needed SIM card update. This update is automatically sent from the network after a SIM card or phone number change has been completed.
To resolve this issue, make you're in T-Mobile coverage and contact T-Mobile Customer Service. Customer Service can send the SIM card update to you.
'REG01: Invalid certificate' error
This message displays when your phone is having trouble connecting to the Wi-Fi Calling service.
You might see alternate versions of this error, such as:
- Invalid Cerificate
To resolve this error, turn off Wi-Fi for 1 minute. Then, turn it back on and try to use Wi-Fi Calling. Visit the Phones page, and select your device. Look for Wi-Fi Calling to access guided steps. If you still see the error, contact T-Mobile Customer Service.
Can't make or receive Wi-Fi calls or call quality issues
If you're experiencing dropped calls, have audio quality issues, or have trouble with Wi-Fi calls, it could be due to a Wi-Fi issue or a phone problem.
To resolve Wi-Fi call issues, follow these steps:
- Make sure of the following:
- You have high-speed Internet service (DSL, cable, FiOS, public Wi-Fi)
- You're connected to Wi-Fi and within 15 feet of the router
- The wireless router is directly connected to the modem
- The wireless router is on the latest firmware version
- You're not near machines or appliances that can cause Wi-Fi interference, such as 2.4Ghz baby monitors, 2.4Ghz cordless, and Bluetooth-enabled devices
- Run a speed test at http://www.speedtest.net. If your download speed or upload speed aren't higher than .25 Mbps, the problem is with the Internet connection.
- Turn off your phone, router, and modem. If you're using public Wi-Fi, jump to step 6.
- Turn on your modem.
- Once the modem shows that it has established an Internet connection, turn on the router.
- Once the router indicates it has connected, turn on your phone handset and try to use Wi-Fi Calling. Visit the Phones page, and select your device. Look for Wi-Fi Calling to access guided steps.
- If you are still having problems with Wi-Fi calls, contact T-Mobile Customer Service.
Can't use text or picture messaging
If you're experiencing messaging issues, it could be due to a Wi-Fi issue or a phone problem.
To resolve this problem, follow these steps:
- Turn off your phone for 30 seconds.
- Turn it back on and try to use Wi-Fi Calling. Visit the Phones page, and select your device. Look for Wi-Fi Calling to access guided steps.
- Try to send a picture message to your own 11-digit mobile number while connected to Wi-Fi Calling.
- If you are still having problems with messaging, contact T-Mobile Customer Service.