Set up phone calls using Microsoft 365 services

[AtanasM]

I have phone numbers already obtained by another provider and the phone devices are Yealink.
Can I use these phone numbers in Microsoft 365?
Is it necessary to use MS Teams or can be used another third party app as well?
What licenses should be assigned?

[#2 · Accepted solution]

@AtanasM 

Phone numbers are generally portable, in that you can transfer a number between different companies supplying a telephony service.

To use Teams as your telephony service there several options

- Use Microsoft as the service provider, through Microsoft Calling Plans.

- Use a third party that can connect their calls into Teams, many exist carriers offer this

- Host a device called an SBC either in your datacenter or somewhere else to connect telephony circuits into Teams,

In all cases you will need the Microsoft Phone System License, it's included in E5 but is a paid addon to E3. Then you either pay Microsoft for a calling plan or pay your preferred operator.

If you have an existing provider I would suggest asking if they can connect your service into Teams, it could be a service they offer. Otherwise you'll be porting your numbers to Microsoft or another provider that can integrate with Teams.