What it does

Teams Phone is the per-user licence that turns Teams into a PBX — it carries the Microsoft 365 Phone System service plan. What you add on top depends on the PSTN route: a Microsoft Calling Plan licence if Microsoft is the carrier, nothing further from Microsoft if an operator or your own SBC carries the calls.

Key facts

• Anyone who needs their own phone number must have licensing that includes both Microsoft Teams and the Microsoft 365 Phone System service plan.
• Three variants of the user licence exist: Microsoft Teams Phone Standard, Microsoft Teams Phone Standard for Frontline Workers, and Microsoft Teams Phone with Calling Plan (the bundle). Each needs a prerequisite base licence.
• Prerequisites for Teams Phone Standard and Teams Phone with Calling Plan include Microsoft 365 Business Basic/Standard/Premium, F1/F3/E3/A3, Microsoft Teams Enterprise, Microsoft Teams EEA, Teams Essentials (AAD Identity), and Office 365 F3/E1/E3/A1/A3. The Frontline variant needs Microsoft 365 F1/F3 or Office 365 F3.
• Microsoft 365 E5 (both legacy with-Teams and E5 no-Teams paired with Teams Enterprise) already includes Phone System, so no separate Teams Phone Standard licence is needed. E5 doesn't include a Calling Plan.
• Calling Plans come as Domestic, International and Pay-As-You-Go, and only in supported countries/regions. The bundle and standalone Calling Plans are both country-dependent.
• Operator Connect, Direct Routing, Teams Phone Mobile and Shared Calling all require a Teams Phone licence but no Microsoft Calling Plan. PSTN charges come from the operator.
• Operator Connect for India needs an India-specific Teams Phone licence from a licensed Indian telecom operator.
• Teams Phone Mobile requires a Teams Phone licence plus an eligible mobile subscription with a participating operator.
• Shared Calling users need Teams Phone only; the number and PSTN licensing sit on the resource account.
• Frontline Teams Phone can only go to users who meet the frontline criteria (single-screen device under 10.9", or a shared primary device).
• SKU part names for PowerShell: MCOEV (Teams Phone Standard and the Frontline variant), MCOTEAMS_ESSENTIALS (Teams Phone with Calling Plan), MCOPSTN1/MCOPSTN2 (Domestic/International Calling Plans).

When to use / skip

Every user who needs a DDI, voicemail, call forwarding to PSTN or a seat in a call queue needs Teams Phone. Users who only ever call colleagues over VoIP don't — Teams-to-Teams calling is in the base licence. The interesting decision isn't whether to buy Teams Phone, it's whether the bundle makes sense. If Calling Plans are available in the country and the client doesn't already own E5, the Teams Phone with Calling Plan bundle is the tidy option. If they're on E5, buying the bundle double-pays for Phone System; buy a standalone Calling Plan instead.

For Direct Routing or Operator Connect customers, there's no Calling Plan at all. Don't let a reseller add one "for safety" — Learn says plainly not to assign a Calling Plan when PSTN is on-premises or third-party.

Configuration decisions

• Which PSTN route per site or user population (Calling Plan, Operator Connect, Direct Routing, Teams Phone Mobile, Shared Calling). Mixed models in one tenant are supported.
• E5 users: standalone Calling Plan or third-party PSTN, never the bundle.
• Frontline users: do they meet the device criteria for the Frontline variant, or do they need full Teams Phone Standard?
• Low-usage staff: Shared Calling against a resource account versus a DDI each.
• Licence assignment via group-based licensing, and how number assignment is sequenced after the licence lands.
• Who owns licence changes on joiners/movers/leavers, given that licence removal drops the number.

Gotchas

• Removing Phone System from a Direct Routing user doesn't just unassign the number — it removes it from the phone number database. For Operator Connect and Calling Plan users the number goes to Unassigned. Either way the user stops taking PSTN calls.
• Swapping SKUs (E3 + Teams Phone to E5, for example) must happen in one save, or one Set-MgUserLicense call with both -AddLicenses and -RemoveLicenses. Two separate saves unassigns the number.
• Group-based licensing makes that worse if the add and remove land in different groups at different times. Plan swaps carefully.
• Calling Plan and bundle availability is per country/region. Check the country and region availability page for every country before quoting a multinational.
• The Frontline variant looks attractive on cost but has eligibility rules in the licence terms. Don't assign it to office workers on laptops.
• Teams Phone Standard must never go on a resource account — that has its own licence.

Consultant notes

• Build the licence matrix per persona (knowledge worker, frontline, reception, queue agent, room, common area phone) before discussing PSTN. Most errors come from mixing those up.
• Where the client's agreement terms decide eligibility (Frontline, EEA, existing-customer rights), say that the Product Terms govern and get the partner to confirm.
• Script licence swaps with both add and remove in one operation, and test on a non-critical user first.
• For Operator Connect and Teams Phone Mobile, the operator's contract carries the PSTN element. Make sure procurement knows that's a separate commercial line from the Microsoft licence.

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Revisit when Calling Plan availability changes in a country you're quoting, or if Microsoft reshapes the Frontline Teams Phone eligibility