Microsoft Teams may occasionally fail to make outbound calls to PSTN.
Either nothing happens, or a strange oops message appears on the screen.
If youre experiencing similar outbound call issues, follow the troubleshooting steps below.
Navigate towww.teams.microsoft.com, and selectUse the web app instead.
Open Teams in Edge or Chrome and verify if you’ve got the option to make outbound calls.
Alternatively, launch the Teams Mobile app and verify if you might make calls.
Maybe theres nothing wrong with your Teams account after all.
Maybe your admin has set up some specific parameters toblock outbound callsor restrict calls to certain numbers.
If this is the case, then theres nothing you’ve got the option to do about that.
Note:Admins can use the troubleshooting suggestions below.
Assign Phone Numbers to Users
If youre an admin, assign individual phone numbers to your users.
Create a Caller ID policy for outbound calls.
Then, assign that policy to all users.
Teams doesnt always pass outgoing calls through the companys main number.
For more information, seeManage caller ID policies in Microsoft Teams.
Create a New Voice Routing Policy
Try creating a new Voice Routing Policy with several PSTN usages.
After you do that, simply assign the new policy to users.
Dont forget to toggle onAllow Private Callingat the tenant level for Microsoft Teams.
Keep in mind that Direct Routing only routes calls to and from users that use the Teams client.
Go to Microsoft Support for more information aboutPhone system direct routing.
If you pair third-party hardware to Teams, be sure to follow your hardware vendors configuration instructions.
For more information, seeConfigure Direct Routingon Microsofts support page.
Note:An integration with the PSTN service is required for users to make outbound PSTN calls from Teams.
Complete the integration process and loop back and try.
Check DNS Record configs
Be sure the DNS record for the SBC FQDN is properly set.
If the controls are incorrect, SBC IP redirects will fail.
Oftentimes, typos in the DNS record can block outbound calls.
confirm the SBC hostname is spelled correctly.
If the DNS record is misspelled, Teams will be looking for the wrong address.
Basically, the service is trying to reach an unreachable DNS name.
Then, delete the app cache, reinstall Teams, and contact your admin.
Then, double-check the DNS Record options to ensure theyre correct.
