How to enable HD Voice calling (Enhanced 4G LTE Mode) on Android 5.1

Google rolled out the Android 5.1 Lollipop update earlier this week, it was a stability and performance update for the most part but it also came with a few new features like native support for multiple SIM cards, Device protection and High Definition Voice calling on compatible phones & carriers.

Of these, the addition of HD Voice calling a.k.a Enhanced 4G LTE Mode is a really helpful feature, and Nexus 6 users will be able to take advantage of it on compatible carriers. However, if you aren’t seeing HD voice calling in action on your device after updating to Android 5.1, do the following:



Head over to “Cellular network settings” from Settings » More » Cellular networks » and toggle Enhanced 4G LTE Mode. In case you don’t see the toggle there, then follow the instructions below to get it:

  1. Open the Dialer app on your phone, and dial *#*#4636#*#*
  2. Select Phone information
  3. Turn On VoLTE Provisioned Flag
  4. Restart phone
  5. Go to Settings » More » Cellular networks » toggle Enhanced 4G LTE Mode, and you’ll get the HD Voice calling on your Android 5.1 running device.

However, your carrier still needs to support this feature. As far as we know, T-Mobile and Verizon in the US supports HD Voice calling.

Via: Twitter
  • Nemo

    What should I do if I cannot change the “Turn On VoLTE Provisioned Flag” button state?

  • happy

    Still not in the settings after a restart.

  • Pramod sencha

    What about nexus 5?

  • Shivaraju

    But in my OPPO a33f phone its unable to turn on the VoLTE provisional flag

    • sumit

      even i facing the same problem how to solve it in oppo f

  • How to turn on VoLTE provisional flag on Infinix x510?

  • umesh

    In my lenovo zuk z1 i can’t on VOLTe provisional flag … What should i do tell me ..

  • Chandrakant Pal

    Volte provisioned flag not showing in Lenovo a6000 Plus.

  • Lakshay

    How to open volte in zte blade s6.

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