Desktop
The dial pad can be used like a typical phone to make a call to a phone number. (You can also type in names or groups.)
To dial a number from Teams, go to Calls 
, and then enter the number of the person you want to reach by using the dial pad located on the left. Then click Call .
To call a person by name, type the name of a person into the dial pad. And to make group calls, enter multiple names and/or numbers, and click Call .
To access your dial pad during a call, go to your call controls and select Dial pad 
.
You can also check out the First things to know about calls in Microsoft Teams article for more calling options and features.
Important: You won't be able to make a 911 emergency call if Teams isn't connected to the internet.
Note: If you don't see the option to dial a number, your org may not have purchased a calling plan. But you can still make calls to other people in Teams.
Mobile
To make a call, tap Calls > 
and enter a phone number. If you’ve enabled the setting to allow access to your phone contacts, tap Calls > Contacts 
on mobile devices and select the person you want to call.
Use the dial pad on your mobile device to dial numbers from your personal phone number and to make emergency calls to your country-specific emergency number.
Note: If you don't see the option to dial a number, your org may not have purchased a calling plan. But you can still make calls to other people in Teams.
Important: You won't be able to make a 911 emergency call if Teams isn't connected to the internet.
Surface Hub
To call a phone number (PSTN) from the Surface Hub, touch Call from the welcome screen, and then tap Dial Pad.
Once you’ve accessed the dial pad, just enter the number you want to call.
