Walk through most small business offices today and you will find a familiar scene: rows of desk phones that ring several times a day, sit idle the rest, and generate a monthly carrier bill that nobody quite remembers negotiating. Meanwhile, the same employees use Microsoft Teams all day for chat, meetings, and file sharing — on their laptops, on their phones, wherever they happen to be working.
The question more small businesses are asking in 2026 is whether those two systems need to exist separately at all. Microsoft Teams Phone System — formerly called Teams Phone and before that Cloud Voice — lets organizations add full PSTN calling capability directly into Teams, replacing traditional desk phones and their associated phone bills with a unified communications platform most employees are already using every day.
This guide explains how the system works, what it costs, which businesses are the right fit, and what a migration actually looks like in practice.
What Teams Phone System actually is (and is not)
Teams itself does not make traditional phone calls out of the box. When you buy a Microsoft 365 Business or Enterprise subscription, you get Teams for internal calls, meetings, and chat — but dialing a customer's mobile number or receiving calls from outside your organization requires an add-on: Teams Phone System.
Teams Phone System is the software PBX layer that enables call routing, auto-attendants, call queues, voicemail, and hold music within your Microsoft 365 tenant. Think of it as the brains of a modern business phone system, hosted in Microsoft's cloud rather than in a box in your server room.
To actually connect Teams to the public telephone network so you can call and receive calls from regular phone numbers, you need one of two options:
- Microsoft Calling Plans: Microsoft becomes your carrier. You purchase phone numbers and a pool of calling minutes directly from Microsoft. This is the simplest path — one vendor, one bill — and works well for businesses with straightforward calling needs within supported countries.
- Operator Connect or Direct Routing: You keep your existing carrier or choose a third-party SIP carrier, and connect their network to Teams. This gives you more flexibility on pricing, number porting, and call volumes, and is often the better choice for businesses with complex call routing, international calling needs, or existing carrier relationships they want to preserve.
Both options deliver the same end-user experience: employees make and receive external calls directly in Teams, from any device, using their business phone number.
What it costs — and how it compares to a traditional phone system
Pricing varies based on your Microsoft 365 plan and the calling option you choose, but here is a representative picture for a small business in 2026:
- Teams Phone Standard add-on: Approximately $10 per user per month on top of your existing Microsoft 365 subscription. This covers the Phone System license — the PBX functionality — for each user who needs calling capability.
- Microsoft Calling Plan (Domestic): Approximately $12–$15 per user per month for a domestic calling plan with a pool of included minutes. International plans add cost.
- Operator Connect / Direct Routing: Pricing varies by carrier, but is often competitive with or lower than Microsoft's own calling plans, particularly for businesses with higher call volumes or international needs.
A 15-person business fully moving to Teams Phone with Microsoft Calling Plans would spend roughly $330–$375 per month on calling, inclusive of licenses and minutes. Compare that to a traditional PBX or hosted VoIP system with per-seat licensing, a separate carrier bill, hardware maintenance, and annual support contracts, and most businesses find the all-in cost comparable or lower — before accounting for the reduction in hardware and the elimination of a separate vendor relationship.
The stronger financial case is often not the monthly savings but the avoided capital expenditure. Traditional phone system hardware — whether on-premises PBX or even a hosted VoIP system with physical handsets — requires periodic hardware refresh. Teams Phone eliminates that cost category entirely for organizations that embrace the softphone model.
Which businesses are the right fit
Teams Phone works particularly well for businesses that:
- Are already on Microsoft 365 Business Standard, Business Premium, or an E-series plan
- Have a distributed or hybrid workforce where employees work from multiple locations or remotely
- Want to consolidate vendors and simplify IT administration
- Have employees who already live in Teams for day-to-day work and would benefit from calling being in the same interface
- Are approaching a hardware refresh on their existing phone system and want to evaluate alternatives before reinvesting
It is a less obvious fit for businesses that:
- Rely heavily on physical conference room phones or analog devices (fax machines, door entry systems, elevator phones) — these require adapters or separate handling
- Have high-volume inbound call centers with complex IVR logic — Teams Phone supports call queues and auto-attendants, but very sophisticated contact center workflows may need a dedicated contact center solution that integrates with Teams rather than replacing it
- Operate in countries where Microsoft Calling Plans are not yet available — in that case, Direct Routing with a local carrier is the required path
The migration path: what it looks like in practice
For a small business making the switch, a well-run Teams Phone migration follows a predictable sequence:
1. License audit and assignment. Confirm which users need calling capability and assign Teams Phone Standard licenses accordingly. Not every user in the organization necessarily needs a PSTN number — reception, sales, and client-facing roles typically do; back-office roles may not.
2. Number porting or new number acquisition. If you are keeping existing business phone numbers — which most businesses want to do — you will port them from your current carrier to Microsoft or your chosen Operator Connect provider. Porting timelines vary by carrier but typically run 2–4 weeks. Plan the cutover date carefully, especially if you have a high-volume main business number.
3. Auto-attendant and call queue configuration. This is where your new phone system's logic is built. Auto-attendants handle inbound greeting and routing ("Press 1 for sales, Press 2 for support"). Call queues manage how calls are distributed among a group of agents and what happens when all agents are busy. These are configured in the Microsoft Teams admin center and require thoughtful design before go-live.
4. User training and device decisions. Most employees adapt quickly — Teams calling works the same way as any other call, just inside an app they already use. The main decision is whether to go fully softphone (laptop and mobile app only) or to deploy Teams-certified desk phones for users who prefer a physical handset. Teams-certified devices from Poly, Yealink, and others provide a familiar experience for employees who want it, without requiring a separate phone system.
5. Parallel running and cutover. Run both systems simultaneously for a short period — typically one to two weeks — before cutting over fully. This gives users time to adjust and gives IT time to catch any routing issues before the old system is decommissioned.
Security and compliance considerations
Teams Phone inherits the security and compliance posture of your Microsoft 365 tenant, which is a significant advantage for businesses already investing in that stack. Call recordings, voicemails, and transcripts can be captured and stored in compliance with your retention policies. Conditional Access policies that control Teams access also apply to calling. And because Teams Phone runs through Microsoft's global network, it benefits from the same uptime guarantees and redundancy as the rest of the platform.
For businesses subject to HIPAA, PCI, or other compliance frameworks, it is worth confirming that your calling configuration — particularly call recording and transcription features — is aligned with your data handling obligations before enabling those capabilities broadly.
The bottom line
For small businesses already on Microsoft 365, Teams Phone System is the most logical path when your current phone system is due for renewal or replacement. It eliminates a separate vendor, puts calling in the same tool your team uses for everything else, and works as well at home or on the road as it does in the office.
The migration does require planning — number porting timelines, auto-attendant design, and user training are not afterthoughts. But for an experienced IT partner who has run the process before, a 15–30 person business can be fully migrated in four to six weeks with minimal disruption.
At Perez Technology Group, we help Central Florida businesses evaluate, plan, and execute Teams Phone migrations as part of a broader Microsoft 365 managed IT engagement. If your current phone system contract is coming up for renewal or your hardware is aging, now is the right time to evaluate whether Teams Phone is the right next step. Reach out for a no-obligation assessment.
