Consultant-focused KB for Microsoft Teams: implementation notes, gotchas and configuration decisions beyond the official docs — across chat and collaboration, meetings, webinars and town halls, Teams Phone, PSTN connectivity (Direct Routing, Operator Connect, Calling Plans, Teams Phone Mobile), auto attendants, call queues and contact centre integration, Teams Rooms and devices, apps and extensibility, Copilot in Teams, administration and governance, security and compliance, network and call quality, and licensing — plus cross-cutting decision guides.
Features Microsoft has announced are going away for Microsoft Teams, grouped by the area they affect. The mirror of the roadmap: what to plan a migration off, not what to adopt. 6 still to take effect · 9 already retired.
The WebRTC-based media optimisation for Teams on VDI reaches end of support on 1 October 2026 for Windows endpoints and end of availability on 1 April 2027. VDI estates need the new optimisation in place before then.
Move to SlimCore-based VDI optimisation for the new Teams client
Microsoft deprecation notice ↗Classic Teams reached end of availability on 1 July 2025 across native clients, VDI and the US government clouds, after end of support in 2024. Users still on it were pointed to the web app.
Move to The new Teams client
Microsoft deprecation notice ↗ACS Chat (including chat in Teams meeting interop), ACS Rooms and the Web and Mobile UI Libraries retire on 30 September 2028. Calling into Teams meetings through the ACS Calling SDK stays supported as a Teams interop scenario. Custom virtual-appointment apps built on the UI Library components need rework.
Move to Teams meeting interop for calling. Teams-native meetings and Virtual Appointments for the rest.
Microsoft deprecation notice ↗Live events, both Teams-produced and external encoder, retired on 30 June 2026. Events scheduled before that date are still supported until 28 February 2027, so find and move any recurring ones before they fail on the day.
Move to Town halls (Teams Premium for the larger audience and advanced production features)
Microsoft deprecation notice ↗ACS Direct Routing retires on 30 September 2028. Calls keep working through the transition for tenants that already have an ACS resource. SBC trunks into ACS need to move to Teams Direct Routing or Operator Connect. The same SBC FQDN can't be registered against ACS and Teams at once.
Move to Teams Direct Routing (keep the SBC and carrier) or Operator Connect (carrier-managed).
Microsoft deprecation notice ↗ACS Number Management (Direct Offer) retires on 30 September 2028. New customers can't acquire ACS numbers after the autumn 2026 cut-off. Existing resources can still buy and port numbers in until the retirement date. Remove numbers before deleting an ACS resource, or they keep billing.
Move to Teams Calling Plan, Operator Connect, Teams Direct Routing or Teams Phone extensibility.
Microsoft deprecation notice ↗After 30 September 2028, ACS Call Automation, Calling SDK, Call Recording, Audio Streaming and Closed Captions are supported only in Teams-aligned scenarios: Teams Phone extensibility, Teams meeting interop or Click-to-Call. Custom IVRs, diallers and contact centre integrations on standalone ACS PSTN need to move, and they need a new major SDK version.
Move to Teams Phone extensibility (TPE) for programmable PSTN voice, or a certified contact centre partner.
Microsoft deprecation notice ↗Microsoft has flagged transfer mode on call queues for deprecation in the second half of 2026. Conference mode is already the default and is required for consult transfer, compliance recording and monitor, whisper and barge.
Move to Conference mode
Microsoft deprecation notice ↗Management of Teams Rooms on Android, Teams phones, panels and SIP devices moves from the Teams admin center to the Teams Rooms Pro Management Portal. Admin center workflows were phased out through September 2026 and the rest retire in October 2026; government clouds follow later.
Move to Teams Rooms Pro Management Portal
Microsoft deprecation notice ↗Support ended on 14 October 2025 for Teams Rooms devices running Windows 10. Rooms need Windows IoT Enterprise or Windows Enterprise on Windows 11; devices whose OEM no longer supports the upgrade move to the end-of-service list.
Move to Windows 11 IoT Enterprise / Enterprise
Microsoft deprecation notice ↗Teams displays are end of support and are not part of the move to the Pro Management Portal. Plan them out of any device refresh.
Move to Teams phones, or the desktop client
Microsoft deprecation notice ↗Creation of new Dataverse for Teams environments ends 15 November 2026, and environments not upgraded to full Dataverse are decommissioned on 30 October 2027. Microsoft's page also lists a suspension date of 15 September 2026, which sits oddly before the creation cut-off, so verify it before relying on it.
Move to Upgrade the environment to full Dataverse, then add apps, flows and agents to Teams from there
Microsoft deprecation notice ↗The TeamsFx SDK is deprecated, with community-only support that ran until September 2026. New Teams apps and bots should be built on the Teams SDK, or the Microsoft 365 Agents SDK for agents that span channels.
Move to Teams SDK / Microsoft 365 Agents SDK
Microsoft deprecation notice ↗Office 365 Connectors were disabled in Teams during May 2026 after several extensions. Anything still posting through a connector webhook URL needs moving; MessageCard payloads work through a Workflows webhook but their buttons no longer render.
Move to Workflows (Power Automate) with the 'When a Teams webhook request is received' trigger
Microsoft deprecation notice ↗Facilitator stopped generating Loop files for meeting notes by 31 July 2026 as part of a back-end migration. Notes now generate as Word documents; live notes during the meeting were not affected.
Move to Word document notes
Microsoft deprecation notice ↗Reporting labels were retired from 15 September 2025. Building and endpoint data for Call Quality Dashboard is now uploaded from Analytics & reports > Building and endpoint data.
Move to Building and endpoint data upload in the Teams admin center
Microsoft deprecation notice ↗From 1 November 2025, a Calling Plan licence on a resource account no longer covers outbound PSTN calls made on behalf of an auto attendant or call queue, including callback and external transfers. Those calls need a funded pay-as-you-go licence or Communications Credits.
Move to Pay-as-you-go Calling Plan or Communications Credits on the resource account
Microsoft deprecation notice ↗