Teams Phone

Microsoft Teams Phone turns Microsoft Teams into a full business phone system. With a Teams Phone licence and one of the connectivity options — Microsoft Calling Plans, Operator Connect, or Direct Routing — Teams users gain a dialler, voicemail, auto attendants, call queues, hunt groups, music on hold, and standard PBX features alongside chat and meetings. Phone numbers are assigned to users or resource accounts in the Teams admin center. Teams Phone Standard is included with Microsoft 365 E5; on other plans it's a paid add-on. Calling Plan minutes are typically billed separately.

Three ways to get a dial tone, and why they're different decisions

Microsoft Calling Plans is the simplest path: Microsoft is the telephony carrier directly, numbers are ported or newly assigned through Microsoft, and minutes are bundled or metered through a Microsoft-billed plan — no separate telecom contract needed, but calling plan availability and rates vary meaningfully by country. Operator Connect lets an organisation keep its existing telecom carrier relationship while that carrier integrates directly with Teams through a Microsoft-certified program — the carrier manages the trunking, but the whole configuration experience stays inside the Teams admin center rather than a separate carrier portal. Direct Routing is the most flexible and most work: an organisation (or its partner) deploys a Session Border Controller (SBC) — its own or a hosted one — connecting Teams to essentially any carrier or existing PBX trunk, at the cost of needing to manage that SBC infrastructure and its own certificate and connectivity requirements.

Worked example

A company with offices in several countries and an existing relationship with a global carrier for cost and compliance reasons chooses Direct Routing rather than Calling Plans, specifically because Calling Plan availability and number-porting rules differ by country and the company needs a single consistent carrier relationship across all of them. It stands up an SBC (via a certified partner's hosted offering, avoiding running the hardware itself) that connects to the carrier's existing SIP trunks on one side and to Teams Phone on the other. Users in every country get the identical Teams calling experience — the same dialler, the same auto attendants — while the actual carrier billing, number ranges, and regulatory compliance for each country continue running through the company's existing global carrier contract rather than through Microsoft directly.

Auto attendants, call queues, and resource accounts

Both auto attendants (an automated "press 1 for sales" menu) and call queues (holding and distributing calls to a group of agents) are configured against a resource account — a special, unlicensed-for-normal-use account type that holds the phone number the feature answers on, distinct from a normal user's own account and number. A common structural mistake is treating resource accounts like regular user accounts for management purposes; they have their own licensing model (a free Phone System - Virtual User license covers most auto attendant and call queue scenarios) and don't need — and shouldn't be assigned — a normal Teams Phone user licence.

Common pitfalls

Number porting between a legacy PBX or carrier and Teams Phone is one of the most common places migrations stall — porting windows, especially across Operator Connect or Direct Routing carriers, need to be planned with real lead time, and a botched port can leave a business number briefly unreachable on either side. The second frequent issue is emergency calling (E911/nomadic 911 in relevant jurisdictions) being treated as an afterthought — Teams Phone requires explicit emergency-location configuration per network site, and skipping it is both a compliance and a genuine safety gap that's easy to miss until it's tested.