If you’re adding PSTN calling to Microsoft Teams — so your staff can make and receive real phone calls within the Teams app — there are two main ways to do it: Direct Routing and Operator Connect. They both achieve the same end result, but through very different means. Here’s how to choose.

Operator Connect: The Simpler Path

Operator Connect is Microsoft’s managed service option. You choose a Microsoft-certified carrier (BT, Gamma, Vodafone, and others are all certified UK operators), and they provision your calling directly through the Microsoft 365 Admin Centre. No SIP trunk configuration, no session border controllers — the carrier handles the technical integration.

Advantages:

• Simpler to set up — provisioned directly in M365 Admin Centre
• Carrier handles SBC and connectivity — less technical overhead
• Easier to manage and troubleshoot — single point of contact
• Microsoft co-manages the service, meaning better Teams integration

Disadvantages:

• Slightly higher cost — certified carriers charge a premium for the managed service
• Less flexibility — you’re limited to what your chosen operator offers
• Fewer carrier options than Direct Routing

Direct Routing: Maximum Flexibility

Direct Routing connects Teams to any SIP trunk via a Session Border Controller (SBC) that you manage. You choose any UK telecoms provider — not just Microsoft-certified ones — and configure the connection yourself (or with the help of a partner like Just Business Phones).

Advantages:

• Lower cost — standard SIP trunk pricing, not carrier premium
• Maximum flexibility — any SIP provider, any call plan
• Can keep existing SIP trunk investment
• More control over routing, failover, and number management

Disadvantages:

• More complex to set up and maintain — requires SBC hardware or cloud SBC
• You (or your partner) are responsible for the SBC
• More technical knowledge required to troubleshoot

Which Should You Choose?

Choose Operator Connect if you want simplicity and don’t have technical resource to manage the connection. Choose Direct Routing if you want lower costs, have an existing SIP trunk you want to reuse, or need more control over your telephony setup.

For most UK SMEs moving to Teams Phone for the first time, Operator Connect is the lower-friction option. For businesses with existing telecoms infrastructure or significant call volumes where cost matters, Direct Routing delivers better value.

At Just Business Phones, we implement both — and we’ll help you model the costs and complexity trade-offs for your specific situation.

Ready to upgrade your business phone system? Get in touch with Just Business Phones today for a free consultation — we’ll help you find the right solution at the right price.