Cisco Webex and Microsoft Teams: Why multi-vendor is the new strategy for voice

Summary: 

Microsoft Teams Phone and Cisco Webex Calling dominate enterprise voice, but in many cases, neither replaces the other. Teams works best for knowledge workers, while Webex serves industries where telephony is critical. Adoption numbers are close, with Teams at 20M seats and Webex at 16M. Enterprises gain flexibility by running both.

For years, the promise was consolidation. One collaboration suite. One calling plan. One place to manage everything. But that vision has never matched reality.

Global enterprises rarely run on a single stack. Teams Phone and Webex Calling dominate the market, yet neither displaces the other outright. Instead, most organizations end up with both. Not by choice, but because business needs force it — acquisitions bring new platforms, regional preferences dictate different providers, compliance blocks single-vendor rollouts.

The pattern is clear: multi-vendor voice isn’t failure. It’s strategy.

The consolidation myth

On paper, standardizing on one platform looks efficient. In practice, enterprises hit barriers quickly:

• Acquisitions bring in incompatible collaboration stacks.
• Different regions favor different ecosystems — Cisco in networking-heavy markets, Microsoft in productivity-led ones.
• Compliance often locks certain workloads to a single platform.
• User adoption slows down when workflows change too drastically.

Consolidation creates as many problems as it solves. Enterprises that push too hard for “one platform to rule them all” usually end up with shadow IT, duplicated systems, and frustrated users. 

Complementary strengths

Treating Teams and Webex as competitors misses the bigger picture. They solve different problems:

• Microsoft Teams Phone is built for knowledge workers who live inside Microsoft 365. Calling is just one part of a broader collaboration experience. For finance, professional services, and public sector, it fits naturally into existing workflows.
• Cisco Webex Calling is voice-first. Its heritage in telephony and devices makes it the stronger choice in industries where calling is critical — healthcare, manufacturing, logistics. Its resilience and integration with Cisco’s contact center stack are differentiators.

Most enterprises discover they don’t need to choose. They need to align each platform to the part of the business it serves best.

Watch now to see Patrick Watson and Tom Arbuthnot how Teams and Webex stack up for enterprise voice.

Adoption numbers

Research shows how close the competition really is. Microsoft Teams Phone has just over 20 million activated seats. Cisco Webex Calling is around 16 million. Zoom Phone trails at roughly 8 million.

The trend matters more than the totals. Teams Phone growth has slowed after its early surge among knowledge workers. Webex Calling is accelerating, driven by Cisco migrating its massive telephony base into the cloud. Both have staying power.

The message for IT leaders: don’t wait for one to “win.” Build for coexistence.

Licensing: two very different models

Licensing is one of the starkest differences between the two.

• Microsoft Teams Phone looks cheap if you’re already on Microsoft 365 E5. But add Calling Plans, Operator Connect, Premium, and Copilot, and costs rise fast. Complexity around stacking licenses makes long-term TCO harder to predict.
• Cisco Webex Calling is simpler. It’s packaged into the Webex Suite, with PSTN through Cloud Connect partners and AI bundled at a lower incremental cost.

One isn’t inherently cheaper than the other. The real difference is predictability. Microsoft ties cost to broad productivity value. Cisco ties it directly to voice.

Related content: The real difference between Webex Calling and Microsoft Teams Phone >>

Contact center and AI

The platforms also diverge sharply in adjacent services.

• Contact center: Teams offers breadth through its certified partner ecosystem, giving enterprises choice. Webex provides depth with a native contact center, streamlining procurement and integration.
• AI: Microsoft spreads Copilot across the enterprise stack — calls, meetings, documents, and email. Cisco applies AI to voice and meetings, focusing on transcription, summarization, and customer experience.

The decision comes down to scope. If AI is a company-wide initiative, Microsoft’s model fits. If voice and customer interaction are the priority, Cisco’s is a cleaner option.

The multi-vendor playbook

Running two platforms adds overhead, but the right strategy turns it into an advantage.

• Policy and governance: Define where each platform fits. Don’t leave it to chance.
• Carrier consolidation: Use a single provider for PSTN across both to simplify routing and reporting.
• Monitoring and compliance: Standardize analytics and call records across platforms.
• User enablement: Train people clearly on when to use which tool. Confusion, not technology, is what undermines adoption.

Handled well, multi-vendor estates provide resilience, flexibility, and leverage. They give enterprises choice instead of lock-in, and negotiating power instead of dependency.

The real choice for IT leaders

The question isn’t whether Teams or Webex “wins.” It’s how IT leaders design coexistence as part of their strategy.

• Use Teams Phone where Microsoft 365 dominates the workflow.
• Use Webex Calling where telephony resilience or contact center depth is critical.
• Tie them together at the carrier layer for consistency and control.

Enterprises that keep fighting for consolidation end up reacting. Enterprises that embrace multi-vendor as strategy stay in control.


The future of enterprise voice isn’t Teams or Webex. It’s Teams and Webex — and the IT leaders who design around that reality will come out ahead.

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