Microsoft Teams Phone System, deployed properly.
Direct Routing vs Operator Connect vs Microsoft Calling Plans — when each is right, what they actually cost, how the deployment works. Engineering-led guide from a UK provider that delivers Teams Phone every week.
From £5 per user, per month.
No PBX hardware to buy and no big upfront cost — cloud phone systems that scale with your team. And because it’s all cloud-delivered, we can have you set up and live within 60 minutes.
What Microsoft Teams Phone System actually is.
Microsoft Teams Phone System turns Microsoft Teams into a fully-functional business phone system. Staff make and receive calls on regular phone numbers using the same Teams app they already use for chat, meetings and document collaboration. The desk phone, the mobile app, and the laptop softphone are all just different surfaces of the same Teams identity.
The technical building blocks: (1) a Microsoft Teams Phone Standard licence per user — the actual Teams software capability. (2) A Microsoft 365 base licence underneath (most Business and Enterprise plans). (3) A way to connect Teams to the public phone network (PSTN) — this is where the three deployment paths diverge.
Teams Phone is the natural answer for organisations already on Microsoft 365 with Teams. It's not a replacement for hosted VoIP if you're not on Microsoft 365 — for non-Microsoft shops, standard hosted VoIP is usually simpler and cheaper. Teams Phone shines specifically because it puts the phone system inside an app staff already use daily, eliminating the "separate phone app" friction of traditional VoIP.
How Teams connects to the public phone network.
Three options. Wildly different in flexibility, cost and complexity. Choosing the right one matters.
Microsoft Calling Plans
What it is: Microsoft provides the calling service directly. You buy minute bundles from Microsoft (Domestic Calling Plan, Domestic and International Calling Plan).
Pros: simplest setup. One supplier (Microsoft) for everything. Configured entirely in the Teams Admin Centre.
Cons: most expensive per-user. Limited country availability. Limited customisation of dial plans. Service quality varies by region.
Typical cost: £8-12 per user per month for UK domestic minutes on top of the Teams Phone licence.
Operator Connect
What it is: a Microsoft-approved UK carrier (like Telexico) connects to your Teams tenant directly. Selected and configured from the Teams Admin Centre.
Pros: fast setup (days, not weeks). UK-based carrier providing UK pricing and support. No Session Border Controller hardware required. Choice of carrier.
Cons: less flexibility than Direct Routing for very complex routing requirements. Limited to participating Operator Connect carriers.
Typical cost: £4-8 per user per month for unlimited UK calls on top of Teams Phone licence.
Direct Routing
What it is: a telecom carrier connects their SIP infrastructure to your Teams tenant via Session Border Controllers (SBCs). Most flexible deployment model.
Pros: maximum flexibility. Supports complex dial plans, multi-site, PBX integration, contact centre integration, specific compliance setups. Choice of any carrier worldwide.
Cons: more configuration than Operator Connect. Requires SBC infrastructure (typically managed by the carrier). Longer setup timeline.
Typical cost: £4-8 per user per month for UK calls + carrier service fees. Similar to Operator Connect for standard deployments; more for complex ones.
Which deployment path is right for your business.
Choose Microsoft Calling Plans if: you want absolute simplicity, one supplier (Microsoft) for everything, simple call patterns (no complex routing or integration), and you're not cost-sensitive. Works best for very small organisations (5-30 users) where the per-user cost is bearable and operational simplicity wins.
Choose Operator Connect if: you want UK-based carrier support and UK domestic call pricing, fast deployment timeline, standard call patterns without complex routing requirements, and you value being able to manage carrier configuration directly from Teams Admin Centre. This is the right answer for most UK SMEs and mid-sized organisations already on Microsoft 365.
Choose Direct Routing if: you have complex deployment requirements — existing on-premises PBX you need Teams to integrate with, contact centre platform needing Teams integration, specific compliance requirements (e.g. PCI-DSS call recording, FCA-mandated recording, sector-specific routing rules), multi-tenant scenarios, or international deployments needing specific country routing. This is the answer for larger organisations or complex deployments.
The honest test: if your phone system requirements fit on one page, Operator Connect is probably right. If they fill multiple pages and include words like "integration", "compliance", "multi-site failover", or "contact centre", Direct Routing is probably right. If you genuinely don't care about flexibility and want the simplest possible answer, Calling Plans work.
What Teams Phone actually costs in 2026.
Microsoft licensing layer (mandatory):
- Microsoft 365 Business Standard / Premium: £10-19 per user per month — base licence including Teams
- Microsoft Teams Phone Standard licence: £6-8 per user per month — adds Phone System capability to Teams
- Microsoft 365 E5 plans: include Teams Phone in the bundle (£42+ per user per month)
Calling service layer (one required):
- Microsoft Calling Plan (Domestic UK): £8-12 per user per month for unlimited UK minutes
- Operator Connect (via UK carrier): typically £4-8 per user per month for unlimited UK domestic
- Direct Routing (via UK carrier): typically £4-8 per user per month + SBC management fee for complex setups
Optional hardware:
- Teams-certified desk phones (Yealink T55A, Poly CCX series, AudioCodes 445HD): £150-350 per handset one-off
- Teams-certified meeting room hardware: £500-3,000 depending on room size
- Headsets (Jabra, Plantronics, Logitech): £40-200 per headset
Typical all-in monthly cost (Operator Connect route, 20-user business already on Microsoft 365):
- Teams Phone licence: 20 × £7 = £140/month
- UK calling via Operator Connect: 20 × £6 = £120/month
- Total for Teams Phone capability: £260/month (£13/user/month)
The Microsoft 365 base subscription is paid regardless — it's not specifically a Teams Phone cost. The marginal Teams Phone cost on top of existing Microsoft 365 is typically £10-15 per user per month. Cheaper than standalone hosted VoIP for organisations already paying for Microsoft 365.
How a Teams Phone rollout actually works.
Week 1 — Discovery and licensing. Confirm Microsoft 365 base licences across all users. Order Teams Phone Standard licences for users who need phone capability. Assess existing phone numbers to be ported. Confirm carrier path (Calling Plans / Operator Connect / Direct Routing).
Week 2 — Number porting initiation. Submit number porting requests to existing UK provider. Porting typically takes 7-14 working days. During porting, configure Teams Phone settings in the Teams Admin Centre: dial plans, emergency calling addresses, voicemail policies, calling policies per user.
Week 2 (parallel) — Carrier configuration. For Operator Connect: add Telexico as the carrier in Teams Admin Centre, assign phone numbers to users. For Direct Routing: configure SBC connection (typically managed by carrier), set up voice routes and PSTN usage records, assign numbers. For Calling Plans: order Microsoft minutes, assign numbers.
Week 3 — Hardware deployment (if applicable). Ship Teams-certified handsets if ordered. Auto-provision via Teams Phone Direct Sign-in. Configure conference room hardware if applicable. Test end-to-end call flow before go-live.
Week 3 — Cutover and training. Numbers port at the agreed cutover time. Old phone system disconnects, Teams becomes the active phone platform. Run user training sessions on making/receiving calls in Teams, transferring, voicemail, mobile app usage. Single named Telexico engineer available during go-live day.
Ongoing — Operational support. Single UK contact for support. Monitoring of call quality, registration, carrier-side issues. Standard SLAs apply. Number additions/removals as needed.
Standard small-to-medium deployment: 2-3 weeks end-to-end. Complex Direct Routing with PBX integration: 4-8 weeks.
Teams alongside on-premises phone systems.
Many UK businesses have an existing on-premises PBX they're not ready to replace. Direct Routing supports several integration patterns:
Coexistence: Teams Phone for some users (often head office, hybrid workers), existing PBX for others (branch offices, specific call centre groups). Calls between groups route via SIP. Common during multi-year migration projects.
Full migration: Teams Phone replaces the PBX entirely. The PBX is decommissioned. All users move to Teams. The fastest path but requires planning around any PBX-specific integrations (e.g. door entry systems, paging systems, specific compliance recording).
Teams as front-end, PBX as back-end: Teams handles the user experience (the app on desktop and mobile), the existing PBX handles call routing logic and integrations. Useful for organisations with complex PBX logic they want to preserve.
Telexico has integrated Teams Phone with most major UK PBX brands — Mitel, Avaya, Cisco, Panasonic, Yeastar, 3CX, Asterisk. The integration pattern depends on the PBX's SIP capability and the specific operational requirements.
Teams Phone has the same network requirements as hosted VoIP.
Teams Phone calls are voice packets traversing your internet connection, same as any VoIP system. Voice quality depends on the network underneath — jitter under 30ms, packet loss under 1%, latency under 150ms RTT, QoS configured to prioritise voice traffic. The VoIP call quality guide covers the technical diagnostics in detail.
The Teams-specific consideration: Microsoft Teams uses its own DSCP marking (46 for voice, 34 for video), and QoS configuration on the office router needs to be aware of this. Without correct QoS, voice quality on Teams Phone degrades the same way it degrades on any VoIP service when the network gets busy.
Telexico-managed Teams Phone deployments include the underlying business internet and connectivity infrastructure configured for Teams traffic. QoS marked correctly. SIP ALG disabled on the router. Failover engineered to preserve in-progress Teams calls. This is the engineering layer that determines whether Teams Phone sounds professional or sounds broken.
UK carrier. Operator Connect & Direct Routing. Engineering depth.
Telexico delivers Microsoft Teams Phone System via both Operator Connect (for standard deployments — faster setup, configured in Teams Admin Centre) and Direct Routing (for complex deployments — PBX integration, contact centre integration, specific compliance requirements).
We also handle the underlying business internet, QoS configuration, router setup, number porting and ongoing support — Teams Phone runs over the same network as any VoIP service, and voice quality depends on the network being engineered correctly underneath. UK-based engineering team, named account contact, no mid-contract price rises.
The free Telexico audit looks at your existing Microsoft 365 setup, current phone system, network infrastructure and operational requirements — then recommends the right Teams Phone deployment path for your operation. If Operator Connect is right, we tell you. If Direct Routing is needed, we explain why. If Teams Phone isn't actually the right answer (e.g. you're not really on Microsoft 365), we'd recommend standard hosted VoIP instead.
Review my current setup.
Not ready to switch yet? Send us your current contracts, bills, or photos of your existing equipment. We'll review what you have, what you're paying, and where you could simplify, consolidate or improve — without any pressure to buy anything from us.
We benchmark your existing broadband, phones, mobile and IT against current UK market pricing and what your business actually needs.
Real engineer review of your current connectivity, voice setup, WiFi, security and continuity — strengths, gaps, and where you're overpaying or underprotected.
We tell you honestly what's available at your postcode — FTTP, leased line, alt-net carriers — and which makes commercial sense for your operation.
For businesses still on ISDN or aging on-premises PBX — an honest cost-and-feature comparison before the 2027 BT switch-off forces a rushed decision.
No hard sell. No fixed package pressure. If we're not a better fit, we'll tell you straight — and recommend what is.
Frequently asked questions
What is Microsoft Teams Phone System?
Microsoft Teams Phone System (formerly Phone System) is a cloud-based phone service integrated directly into Microsoft Teams. It turns Teams into a fully-functional business phone system — staff can make and receive calls on regular phone numbers using the same Teams app they already use for chat, meetings and collaboration. It requires a Teams Phone licence on top of Microsoft 365, plus a way to connect to the PSTN (public phone network) for actual calls.
What's the difference between Direct Routing, Operator Connect, and Calling Plans?
Three different ways to connect Teams Phone to the public phone network. (1) Microsoft Calling Plans: Microsoft provides the phone service directly, you buy minutes from Microsoft. Simplest but most expensive and limited to specific countries. (2) Operator Connect: a Microsoft-approved telecom carrier (like Telexico) plugs directly into your Teams tenant via the Microsoft Teams Admin Centre. Faster setup than Direct Routing. (3) Direct Routing: a telecom carrier connects their SIP infrastructure to your Teams tenant via Session Border Controllers (SBCs). Most flexible, supports complex deployments, requires more configuration. UK businesses typically choose Direct Routing or Operator Connect for cost and flexibility reasons.
How much does Microsoft Teams Phone System cost?
Three cost components. (1) Microsoft Teams Phone licence: £6-8/user/month for the Teams Phone Standard licence. Some Microsoft 365 plans (E5) include it. (2) Calling minutes or carrier service: varies by route. Microsoft Calling Plans: £8-12/user/month for UK domestic. Carrier route (Direct Routing or Operator Connect via providers like Telexico): typically £4-8/user/month for unlimited UK calls plus call-out rates for international. (3) Optional handsets if you want desk phones (not required — Teams works fine with computer + headset and mobile apps). Typical all-in cost: £10-18/user/month.
Do I need Microsoft 365 to use Teams Phone?
Yes — Microsoft Teams Phone System requires an underlying Microsoft 365 licence that includes Microsoft Teams (most Business and Enterprise plans). On top of the base 365 licence, you add the Teams Phone licence and the calling service. If your organisation is already on Microsoft 365 with Teams, adding Teams Phone is straightforward. If you're not on Microsoft 365 at all, Teams Phone usually doesn't make sense as a standalone product — pure hosted VoIP from a UK telecom provider is typically simpler and cheaper.
Will Teams Phone replace my existing business phones?
Yes — Teams Phone can fully replace traditional business phone systems, hosted VoIP, and the office desk phones. Calls ring through the Teams app on laptops, mobile phones (via the Teams mobile app), or compatible desk phones (Yealink, Poly, AudioCodes have Teams-certified hardware). Staff dial extensions or external numbers, transfer calls, hold calls, conference, do everything a traditional phone system does — but inside the same Teams app where they already work.
Can I keep my existing phone numbers?
Yes — UK number porting to Teams Phone works the same way as porting to any other VoIP service. Geographic numbers (01, 02), non-geographic (03, 0800, 0345), and direct dial-ins all port to the carrier providing your Teams Phone calling service (e.g. Telexico via Operator Connect or Direct Routing). Porting typically takes 7-14 working days. The numbers then route to Teams via the carrier's infrastructure.
Which deployment model is right for my business?
Honest decision logic: (1) Microsoft Calling Plans — only consider if you want absolute simplicity and don't mind paying premium per-user pricing. Works for small organisations (10-50 users) wanting one supplier for everything. (2) Operator Connect — best for most UK businesses already on Microsoft 365 wanting reasonable cost, fast setup and choice of UK carrier. Configurable in Teams Admin Centre. (3) Direct Routing — best for complex deployments needing SIP trunk integration with existing PBX, advanced call routing, contact centre integration, or specific compliance requirements. Most flexible but more configuration. Telexico offers both Operator Connect and Direct Routing — the right one depends on your operational complexity.
Can Telexico set up Teams Phone for my business?
Yes. Telexico is a UK telecom provider offering Teams Phone via both Operator Connect (faster setup, configured in Teams Admin Centre) and Direct Routing (more flexible, supports complex requirements). We handle licensing, number porting, SBC configuration where needed, dial plan setup, and end-user training. The implementation typically takes 7-14 working days for a standard deployment. We also handle the underlying business broadband and connectivity if needed — voice quality on Teams Phone depends on the network underneath, same as any VoIP service.
Tailored around your business.
Send us your current setup. We'll review what you have, what you pay, and where we can simplify, consolidate or improve it — no hard sell, no fixed-package pressure.