Microsoft Teams Calling for Business: Add Phone Calls to Teams

The Problem with Traditional Phone Systems

Many UK businesses still operate on legacy PBX phone systems — hardware that requires maintenance, lacks remote working capability, and is increasingly difficult to support as hardware ages and replacement parts become scarce. Managing a separate phone system alongside Microsoft 365 adds complexity and cost.

92% of hybrid workers rely daily on Microsoft 365 or Teams for communication and data access. (SQ Magazine)

Microsoft Teams Phone has surpassed 26 million PSTN users worldwide as of December 2025 — up from 20 million in April 2024, representing 30% growth in 20 months. (UC Today)

28% of UK employees work in a hybrid setup (office + home); 16% are fully remote (ONS 2025). (Mollearn)

Teams Phone eliminates this separation. By handling calls through the same application your team already uses for meetings and messaging, you reduce the number of communication tools, simplify IT management, and give employees a better experience — particularly for remote and hybrid workers who do not have a physical desk phone.

Teams Direct Routing vs Operator Connect

There are two main ways to connect Microsoft Teams Phone to the public telephone network. Direct Routing uses a Session Border Controller (SBC) — hardware or virtual — to connect Teams to a chosen telephony carrier. This gives maximum flexibility in carrier choice and pricing, and allows integration with legacy phone systems during transition. Operator Connect is a simpler integration where a Microsoft-certified operator (like AMVIA) provides call plans directly through the Teams admin centre, requiring no SBC hardware.

AMVIA recommends the right connection method based on your current infrastructure, number porting requirements, call volume, and whether any legacy telephony equipment needs to remain in service during transition.

Number Porting

Your existing business phone numbers can be ported to Teams Phone — staff continue to receive calls on their current numbers through Teams rather than through the old phone system. AMVIA manages the number porting process, coordinating with your current provider and Microsoft to transfer numbers without service interruption.

Where local or geographic numbers are important to your business, AMVIA ensures these are preserved in the migration. Virtual geographic numbers (01/02 numbers that ring into a cloud-based system) are particularly straightforward to port and maintain.

Licensing Requirements

Teams Phone capability requires a Microsoft Teams Phone System licence, which is included in Microsoft 365 E5 or available as a standalone add-on. Calling plans — the minutes or connectivity required to make external calls — can be provided through Microsoft's own calling plans or through a Direct Routing carrier like AMVIA.

AMVIA advises on the most cost-effective licensing combination for your specific usage profile — the right answer depends on your call volumes, whether you need international calling, and your existing Microsoft 365 licence tier.

Auto-Attendants and Call Queues

Teams Phone includes auto-attendant capability — an interactive greeting that routes callers to the right person or department based on their input. Call queues manage inbound call volumes, placing callers in a queue when all agents are busy and distributing calls as agents become available. AMVIA configures auto-attendants and call queues to match your current call routing logic, or redesigns call flows if your existing setup has grown unwieldy over time.

Integration with Existing Infrastructure

Where businesses have analog lines, fax machines, door entry systems, or alarm lines connected to their current phone system, these need to be accounted for in a Teams Phone migration. AMVIA conducts a full audit of your current telephony before recommending a migration approach, ensuring that legacy analog requirements are handled — typically through an analog telephone adapter (ATA) or similar bridging device — without disrupting operational processes.

AMVIA's Managed Teams Phone Service

AMVIA manages the full Teams Phone deployment — licensing, number porting, call routing configuration, and user training. Ongoing, AMVIA supports additions, changes, and fault resolution. Monthly call reporting is available for businesses that need to monitor call volumes or track response times. AMVIA provides UK-based support for Teams Phone issues, supplementing Microsoft's own support with hands-on configuration expertise.