Microsoft Teams Phone for UK Businesses: Calling Plans vs Operator Connect vs Direct Routing (2026)

Quick answer

Yes, Microsoft Teams can be your business phone system, and for a business that already lives in Microsoft 365 it is often the right one. Teams Phone gives every licensed user a real UK number, a dial pad in the Teams they already use, voicemail, call queues and auto attendants. The decision is not whether but how: there are three ways to connect Teams to the public phone network - Microsoft Calling Plans, Operator Connect and Direct Routing - and they differ in cost per user, how flexibly you can bring your numbers, and how well they cope with a busy reception, compliance recording and desk phones. For most UK businesses under a hundred people, Operator Connect through a UK carrier is the sweet spot. For businesses with a busy front desk, a hybrid of Teams for knowledge workers and a conventional hosted system for reception is usually better than forcing everything into Teams.

We support both Microsoft 365 and telephony, which is why we get asked this more than any other phone question, and why this guide is franker than a Microsoft partner's or a telecoms reseller's would be: each has a reason to steer you one way. If you want the routes priced against your actual licences and headcount, get a no-obligation quote and we will lay out all three.

What Teams Phone is, and what it is not

Out of the box, Teams makes calls between Teams users. Teams Phone (Microsoft's name for what used to be called Phone System) adds the telephony layer: a personal phone number, a dial pad, voicemail with transcription, call forwarding and simultaneous ring, call transfer, hold and park, and the two building blocks of a small-business phone system - auto attendants (press 1 for sales) and call queues (ring these six people, play music while they wait). It works on the Teams desktop and mobile apps and on Teams-certified desk phones from Yealink, Poly and others.

What it does not include is the connection to the public telephone network. A Teams Phone licence on its own can call other Teams users; to ring a customer's mobile or receive a call from the outside world you need one of the three routes below. Understanding that split - licence plus route - is the whole trick to comparing quotes, because a "Teams phone system" price from one supplier may include the route and another may not.

The three routes compared

Calling Plans are Microsoft acting as your carrier. Nothing to integrate, one bill, and a good fit for a ten-person professional services firm that wants phones to "just be in Teams". The cost per minute is the highest of the three and international calling is where it bites.

Operator Connect is the route most UK businesses should look at first. You pick a certified carrier from a list inside the Teams admin centre, connect it, and your numbers and minutes come from that carrier at carrier prices while the management stays in Teams. There is no SBC to run and no SIP to understand. Carriers compete on price and bundles, so an unlimited-UK-minutes seat is often a few pounds a month.

Direct Routing connects Teams to SIP trunks through a session border controller - a box or cloud service that translates between the two worlds. It is the most flexible: any SIP provider, analogue devices through the SBC, local survivability, and routing rules Operator Connect cannot express. It is also the route where projects go wrong, because someone has to own the SBC. It makes sense for businesses already on SIP trunks, with several sites, or with a partner who runs SBCs for a living.

What Teams does well as a phone system

For the majority of staff in a typical UK SME - people who make and take a handful of calls a day between Teams meetings - Teams Phone is genuinely good. Presence is native: nobody is put through to someone in a meeting. Voicemail transcripts land in Outlook. The mobile app means a work number on a personal phone without giving out the personal number, which is exactly the problem hosted telephony solves for hybrid teams. Auto attendants and call queues cover the basics of a small front desk, and resource accounts for them are licensed at no charge. Certified desk phones exist for the people who want a handset.

It also collapses two systems into one. Every hosted telephony provider has an app; Teams Phone means one fewer app, one fewer login and one fewer supplier.

Where Teams falls short, and what fills the gap

This is the part suppliers on either side gloss over. Teams was built as a collaboration tool that learned to make phone calls, and it shows in five places.

1. The busy reception. A receptionist handling forty calls an hour needs a console: see who is on the phone, drag a call to a person, park it, retrieve it. Teams' native experience is not that. Third-party attendant consoles exist and work, but they are an extra product and an extra cost.
2. Compliance recording. Teams' built-in recording is for meetings, not regulation. If the FCA, your insurer or your contracts require call recording, you need a certified third-party recorder - more on the requirements in our guide to call recording for compliance.
3. Analogue and odd devices. Door entry, lift phones, fax machines, the warehouse phone on a wall: none of these speak Teams. Direct Routing through an SBC with analogue ports handles them; Calling Plans cannot.
4. Contact-centre features. Skills-based routing, wallboards, callbacks and detailed queue analytics are thin natively. Teams-certified contact centre products fill the gap, at contact-centre prices.
5. Dependency. If Microsoft 365 has a bad day, Teams Phone has a bad day. A conventional hosted platform is a separate system, which for a business whose phones are its income is a real consideration rather than a theoretical one.

None of these is a reason not to use Teams. They are the reasons the most common good outcome is a hybrid: Teams Phone for the office staff, a conventional hosted telephony system for reception, the sales floor or the support desk, with the two connected so calls transfer cleanly between them. We build more of those than pure Teams deployments.

What it costs

Two lines on the invoice, and it is worth keeping them separate when you compare quotes. As an illustrative September 2026 guide, ex VAT:

• The Teams Phone licence: a per-user add-on to Microsoft 365 Business Basic, Standard or Premium and to E1 and E3, typically single-digit pounds per user per month; it is bundled into E5 and into Microsoft's Teams Phone with Calling Plan bundles. Check current Microsoft pricing, which changes.
• The route: roughly £9 to £11 per user for a Microsoft domestic Calling Plan; roughly £3 to £8 per user for a UK-minutes bundle through Operator Connect; roughly £3 to £8 per user or per channel for Direct Routing plus the SBC (a one-off in the low thousands, or a monthly hosted-SBC fee) and set-up.
• The extras where you need them: attendant console, compliance recording, contact-centre features, desk phones (£120 to £300 for Teams-certified handsets).

Set against a conventional hosted seat at roughly £8 to £20 per user per month all-in, Teams Phone via Operator Connect lands in the same territory for a business that already pays for the underlying Microsoft 365 licences. It is rarely dramatically cheaper and rarely dramatically dearer; the decision should be made on fit, not price. Our hosted telephony pricing guide has the comparison worked through.

How a Teams Phone migration works

1. Licence audit. Which Microsoft 365 plans do you hold, who needs a full phone and who only needs to make the odd call. This alone often halves the seat count.
2. Choose the route. Calling Plans for simplicity, Operator Connect for most, Direct Routing where the requirements demand it. Decide now whether reception stays on a hosted system.
3. Numbers. Port your existing numbers to Microsoft or the carrier (number porting works the same way), or order new ones. Port dates drive the timeline.
4. Build. Auto attendants, call queues, holiday routing, voicemail policies, caller ID rules, desk phones enrolled.
5. Emergency calling. Configure 999 location information for every site and for remote workers. In the UK this is a regulatory requirement for VoIP services, and it is the step most DIY deployments miss.
6. Pilot, then port. A department goes first for a week; the port completes; the old lines are ceased. Typical elapsed time two to five weeks, mostly waiting on the port.

Teams Phone or a hosted system: a quick decision guide

• Everyone is in Microsoft 365, nobody sits on the phone all day, no recording requirement: Teams Phone via Operator Connect. Clean and cheap.
• A busy reception, a sales or support team, or FCA-style recording: hosted telephony for those teams, Teams Phone for the rest, connected.
• Several sites, analogue devices, an existing SIP contract or a partner who runs SBCs: Direct Routing, possibly with hosted for reception.
• No Microsoft 365, or Google Workspace: a hosted system. Teams Phone without Microsoft 365 makes no sense.
• You want the phones to keep working if Microsoft 365 does not: at least reception on a separate hosted platform.

The bottom line

Microsoft Teams is a perfectly good phone system for most of the people in most UK businesses, and Operator Connect has made it easy to give it real UK numbers at carrier prices. Where it struggles - the front desk, compliance recording, odd devices, contact-centre work - a conventional hosted system alongside it is the answer, not a reason to avoid it. The mistake is letting a supplier who only sells one of the two decide for you.

We sell and support both. Get a no-obligation quote or call 0333 006 9399, tell us your Microsoft 365 licences and headcount, and we will price Teams Phone on each route against a hosted system and say plainly which we would choose for you. Our hosted telephony service page explains how the quote works.

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