In short
Teams calling to and from ordinary phone numbers needs a Teams Phone licence for each user and a connection to the phone network. Our Teams calling service provides that connection with Direct Routing run for you: your existing numbers kept, itemised call billing and Teams Phone licences supplied. Forever Systems can quote and set it up.
Get a quote for Teams calling
Tell us roughly how many users or sites you have and we will come back to you with options and a quote.
Our Teams calling service
Our Teams calling service connects Microsoft Teams Phone to the UK phone network for you. It uses Microsoft's Direct Routing model, run for you as a managed service, so the equipment that links Teams to the carrier sits in the cloud and nothing is installed on your site.
- Your existing numbers kept, ported from your current provider
- Calls in the Teams apps on Windows, Mac, iOS and Android
- Menus and department groups built with Teams Phone auto attendants and call queues
- Itemised call billing, with a minutes bundle available on request
- Optional call recording
- Teams Phone licences supplied, so calls and licences are quoted in one place
Licences can be billed monthly, with terms confirmed at quote. Contact us for a Teams calling quote.
How the service works
- Each user holds a plan that includes Teams, plus a Teams Phone licence. We can supply the Teams Phone licence.
- Your numbers are ported to the service and assigned to users, auto attendants and call queues in Teams.
- Calls pass between Teams and the phone network through certified Session Border Controllers run in the cloud.
- You manage users in the Microsoft 365 and Teams admin centres you already use, and we look after call routing and the carrier side.
No Microsoft Calling Plan is needed. Microsoft Teams Direct Routing explains the model in full.
Microsoft's four ways to connect Teams to the phone network
Microsoft lists four connectivity models (opens in a new tab) for Teams Phone, and says more than one can be used in the same tenant.
| Option | Who carries the calls | Who manages it | Number types supported |
|---|---|---|---|
| Microsoft Teams Calling Plans | Microsoft | Microsoft | User, auto attendant, call queue and conferencing numbers |
| Operator Connect | A Microsoft-certified operator | Shared between the operator and Microsoft Teams | User, auto attendant, call queue and conferencing numbers |
| Teams Phone Mobile | A participating mobile operator | The mobile operator | User numbers only |
| Direct Routing | A carrier of your choice, through a certified Session Border Controller | You, an integrator or a Direct Routing as a Service provider | User, auto attendant, call queue and conferencing numbers |
Teams Phone Mobile makes the number on a user's company SIM their Teams number as well, so one business number works on the mobile and in Teams. It is sold through a mobile network, and Teams Phone Mobile on EE Business (opens in a new tab) is covered on our business mobile site.
Operator Connect vs Direct Routing vs Calling Plans compares the options in more detail.
Not sure which option fits? Ask us
Tell us what you need and we will help you choose the right option.
Can Teams call landlines and mobiles?
Yes, once two things are in place. Microsoft says calls between Teams users in an organisation stay inside Teams and never touch the public phone network. To make and receive external calls, a user needs a Teams Phone licence and the tenant needs a connection to the PSTN (public switched telephone network), which also brings the phone numbers.
With both in place, people dial landlines, mobiles and international numbers from the Teams dial pad, and callers reach them on a normal business number. The calls themselves travel over the internet as voice over IP (VoIP) until they reach the carrier.
Who our Teams calling service suits
- Organisations that already work in Microsoft 365 and Teams every day
- Those that want to keep their existing numbers
- Those that prefer itemised call billing to pooled plan minutes
- Organisations replacing an older phone system or ISDN lines
- Schools, charities and public sector bodies
If you want to keep an existing phone system and still call from Teams, see Call2Teams.
Need help choosing?
We will recommend what fits your organisation and explain why, in plain English.
Getting started
- Tell us about your users, numbers and sites, and anything else on your lines such as door entry or alarms.
- We check the Microsoft 365 plans you hold and the Teams Phone licences needed.
- We plan menus, department groups, opening hours and recording with you, and arrange the number port.
- We set up Teams and test calls with you.
- On the port date your numbers ring in Teams.
Teams Phone setup describes the steps in more detail. Contact us to start.
Sources (checked 11 November 2026): Microsoft Learn, "PSTN connectivity options", "What is Teams Phone", "Plan for Teams Phone Mobile", "Plan Direct Routing" and "Microsoft Teams add-on licenses".
Ways to connect Teams to the phone network
How Forever Systems helps with Teams Phone
Forever Systems can quote and set up Microsoft Teams Phone for your organisation and connect it to the phone network.
- Licence and calling check: we look at the Microsoft 365 plan you hold and recommend the Teams Phone licences and calling option that fit
- Numbers kept: we plan and manage the porting of your existing numbers
- Call flows set up: auto attendants, call queues and opening hours built and tested with you
- Works with what you use: the Teams apps on desktop and mobile
- Licensing in one place: licences can be billed monthly, with terms confirmed at quote
We work with businesses, schools, charities and public sector organisations. Pricing depends on users, licences and calling, so ask us for a quote.
Frequently asked questions
Can Teams call a landline?
Yes. A user with a Teams Phone licence and a connection to the phone network can call landlines and mobiles from the Teams dial pad and receive calls on a business number. Without those, Teams calls only reach other Teams users.
Can a company make and receive external calls in Teams?
Yes. Microsoft Teams Phone adds external calling to Teams once the organisation has a connection to the phone network: a Microsoft Calling Plan, Operator Connect, Teams Phone Mobile or Direct Routing, such as our Teams calling service.
What is PSTN calling in Microsoft Teams?
PSTN calling means calls between Teams and the public switched telephone network: ordinary landline and mobile numbers. It needs a Teams Phone licence for each user and a connection to the phone network, which also supplies the phone numbers.
Do we need a Microsoft Calling Plan for Teams calling?
No. A Calling Plan is one of four options. With Operator Connect, Teams Phone Mobile or Direct Routing, including our Teams calling service, the calls are carried by an operator or carrier and no Calling Plan is needed.
Can we keep our numbers when calling moves to Teams?
Usually, yes. Our Teams calling service is built to keep existing numbers: we port them from your current provider and assign them to users, auto attendants and call queues in Teams.
Is Teams calling a VoIP service?
Yes. Teams carries calls over the internet as voice over IP. Calls between Teams users stay inside Teams, and calls to ordinary numbers pass to the phone network through the calling service connected to your tenant.
Still have a question about Teams calling?
Ask us and a member of our team will get back to you.