Teams Phone: Calling Plans vs Operator Connect vs Direct Routing

Teams Phone: Calling Plans vs Operator Connect vs Direct Routing — Microsoft Teams Phone gives you the dial pad, but it does not connect to the public phone network by default. There are three ways to add that connection, and choosing wrong can cost you money or flexibility for years. Here is the plain-English breakdown.

Why this choice exists at all

Teams Phone is the calling layer inside Microsoft 365, but placing and receiving calls to ordinary phone numbers requires PSTN connectivity — a link to the public switched telephone network. Microsoft offers three models for that link. Everything else about Teams calling stays identical regardless of which you choose; this decision is purely about the pipe to the outside world, which is exactly why it gets underthought.

Microsoft Calling Plans: simplest, all-Microsoft

With Calling Plans, Microsoft is your carrier. You buy a plan per user, numbers come from Microsoft, and everything bills on your Microsoft invoice.

• Fastest to turn on; minimal setup
• One vendor, one bill, easiest administration
• Best for smaller, all-Microsoft organizations that value simplicity
• Downside: fixed per-user pricing gets expensive at scale; country availability varies

Operator Connect: carrier choice with Microsoft simplicity

Operator Connect lets you pick a participating carrier whose service is integrated directly into the Teams admin center. You get competitive carrier pricing and a real telecom relationship, while provisioning stays nearly as simple as Calling Plans.

• Better economics than Calling Plans through carrier competition
• Numbers and provisioning managed from the same Teams console
• A carrier you can negotiate with and call for support
• The quiet default for many mid-sized businesses

Direct Routing: maximum control and flexibility

Direct Routing connects Teams to a Session Border Controller and the carrier of your choice. It offers the most control and the strongest pricing leverage, at the cost of complexity.

• Keep an existing carrier contract and negotiate freely
• Support analog devices, paging, and contact-center integrations
• Full control over call routing and policy
• Requires design, an SBC, and ongoing management — real engineering, not a toggle

Picking the right model

Smaller, all-Microsoft shops that value simplicity lean toward Calling Plans or Operator Connect. Organizations with existing carrier relationships, analog devices, or complex routing lean toward Direct Routing. Because the decision has recurring cost implications, it is worth modeling each option against your actual call volume and number count before committing.

Leonidas models the Teams Phone PSTN options against real usage as part of a unified communications engagement so the math drives the choice, not whatever is easiest to sell. Request a free assessment to compare them for your environment.