Thank you for contacting us at Authy Support and I am sorry to hear that you are experiencing issues with calls in China.
Unfortunately, the local regulation in China introduced new measures that also affect verification/authentication codes provided via voice calls:
– No calls allowed with a duration shorter than 3 minutes
– No unsolicited marketing calls
– No high volume of repeated calls from the same origination (From) Number within a rolling hour
– No calls allowed from invalid, modified, spoofed or restricted origination (From) Numbers
– Calls must be sent from an international, non-China number when making calls to China
As you can see – the calls we place for 2FA are shorter than 3 minutes, therefore we are not able to route them.
Our team is looking for a solution and whitelisting, but at the moment we cannot guarantee a timeline for a fix.
Could you check our SMS functionality for China, this is the only workaround we can provide at the moment.