Manage your call settings in Teams
To change your settings, click your profile picture at the top of Teams, then Settings. There are a few different places with call settings: General, Devices, and Calls.
Note: If you don't see Calls 
on the left side of Teams, talk to your IT admin.
Add and remove delegates
To manage who can make and receive calls on your behalf, select your profile picture at the top of teams, then Settings > General.
Find the Delegation section and choose Manage delegates. There you can see who you're a delegate for, and add and remove your own delegates.
When you add someone as a delegate, you'll see some permissions settings. If you want, you can enable your delegates to make and receive calls on your behalf, as well as let them change your call and delegate settings.
Learn more about delegates here.
Change your default mic, speaker, or camera
To select the mic, speaker, and camera you want Teams to use for calls and meetings, click your profile picture at the top of Teams, then Settings > Devices.
Under Audio devices, pick the speaker and mic you want Teams to use by default.
Under Camera, select the camera you want Teams to use, and see a preview of that camera's video.
If you have multiple certified devices connected to your computer, you can set one as your secondary ringer, which means it'll ring when a call comes in. Answer incoming calls on any device—not just the ones that ring.
Make a test call
To make a test call, select your profile picture, then Settings > Devices.
Choose Make a test call under Audio devices.
In a test call, you'll see how your mic, speaker, and camera are working. Follow the instructions from Test Call Bot and record a short message. The message will play back for you. After that, you'll get a summary of the test call, and you can go to your device settings to make changes.
Notes:
The test call feature is only available in English for now. Additional languages are coming soon.
We'll delete your test recording immediately after the call. It won't be retained or used by Microsoft.
The test call feature is currently unavailable for Teams on the web.
Set your call answering rules
To set your call answering rules, click your profile picture at the top of the app, then Settings > Calls.
Choose how you want Teams to handle your incoming calls in the section for Call answering rules.
Select Forward my calls if that's what you want to do. If you want simultaneous ring, click Calls ring me and select others under Also ring.
Choose what to do with calls that go unanswered under If unanswered.
Adjust your voicemail settings
To change your voicemail settings, click your profile picture, then Settings > Calls.
In the Voicemail section, click Configure voicemail. That's where you'll find all your voicemail settings.
Voicemail greeting
To record a new voicemail greeting, select Record a greeting and follow the instructions to record your message.
Call answer rules
To change how calls are handled once they reach your voicemail, go to Call answer rules. By default, Teams will play your voicemail greeting and allow the caller to record a message. You have some other options, though:
Let the caller record a message.
Let the caller record a message or be transferred to someone else.
End the call without playing your greeting.
Play your greeting and end the call.
Transfer the call to someone else.
If you choose an option that includes transferring the call, set the name or number where you want your calls to go under Where should they be transferred?
Default greeting language
Change your default greeting language by selecting the language you want under Greeting language.
Text-to-speech voicemail greeting
To use a text-to-speech voicemail greeting, type one in Your custom greeting under Text-to-speech customized greeting.
Note: If you've recorded a greeting, it'll override the text-to-speech option.
Out of office voicemail greeting
Type your out of office greeting in Your custom out of office greeting under Text-to-speech customized greeting, then choose when you'd like it to play under Out of office greeting.
Choose ringtones
Set your preferred ringtones by clicking on your profile picture at the top of the app and then choosing Settings > Calls.
There, under Ringtones, you can choose separate ringtones for your normal calls, forwarded calls, and delegated calls so you're able to tell them apart.
Turn on Text Telephone (TTY)
Select your profile picture at the top of Teams, then Settings > Calls.
In the Accessibility section, click Turn on TTY mode.
Manage blocked numbers
To view and manage the numbers you've blocked, click on your profile picture and go to Settings > Privacy.
Select Edit blocked contacts under Blocked contacts to see any numbers you've blocked and remove them from the list.
To block anonymous calls, select Block calls with no caller ID.
Manage call queue notifications
If you're a call queue agent, you can turn notifications off or on for each of your queues.
Go to Settings > Calls, and scroll down to Call queues to see a list of your queues. Click the toggle switch next to each queue to turn notifications on or off.