How should China Unicom turn off HD calls?

If VOLTE HD phone service needs to be turned off, you can edit TDVOLTE and send it to 100 10 to turn it off, and reply "Y" to confirm the turn-off of VoLTE function, which will take effect immediately after the successful turn-off, subject to the receipt of the confirmation message.

Tips: Take Jiangsu Province as an example. There may be differences in policies among provinces and cities, and the attribution policy shall prevail.