A team can still be running Azure Communication Services today and discover that its next product decision has already been made for it. Microsoft’s guide says the standalone Azure Communication Services offering retires on September 30, 2028. That date does not describe one uniform migration to Teams. Microsoft has separated ACS capabilities into services that retire, services that continue only in supported Teams-aligned scenarios, and integrated solutions or alternative destinations that follow their own path.
The practical recommendation is to inventory your ACS dependencies by service and classify each one before choosing a replacement. A product using ACS Rooms or the Web UI Library has a different problem from a calling application that can operate through Teams interoperability. A business using ACS Email, SMS, WhatsApp, or Job Router may be looking at a different destination altogether. Treating every workload as a Teams migration creates the wrong project plan.
What Microsoft is actually retiring
Microsoft defines retirement as permanent removal from Azure. Once the retirement date arrives, the affected service, feature, model, or SDK will no longer be available or supported under ACS. The authoritative ACS retirement and breaking-changes guide identifies the following services and SDKs as retired:
- ACS Email
- ACS SMS
- ACS Advanced Messaging with WhatsApp
- ACS Chat
- ACS Chat for Teams Meeting Interop
- ACS Rooms
- ACS Number Management (Direct Offer)
- ACS Direct Routing
- ACS Job Router
- ACS Web UI Library SDK
- ACS Mobile UI Library SDK
These entries belong to the retirement category. Microsoft’s guide points to different destinations depending on the workload. Email customers are directed toward options including Microsoft 365 High Volume Email, Exchange Online, and Marketplace partners. Job Router guidance points toward Dynamics 365 Contact Center and named partners. Direct Routing and number-management workloads have Teams and telephony destinations. Those recommendations describe possible paths for individual services; they do not turn the ACS portfolio into a single Teams product.
The distinction matters for planning. An application that uses several ACS services may have several migration tracks, each with a different identity model, API surface, operational owner, and commercial structure. ACS Chat also has separate Microsoft guidance stating that Graph Chat is not a drop-in replacement and brings Teams identities, licensing, tenant policies, and governance into the design. The replacement question therefore starts with the service your application actually uses.
What continues, with a new condition
Microsoft classifies several capabilities as affected by breaking changes rather than as outright retirements. Those services remain available after the retirement date, but continued support requires use with a supported Teams-aligned service. Microsoft specifically lists Teams Phone Extensibility, Microsoft Teams Meeting Interoperability, and Microsoft Teams Click-2-Call for Teams Voice Apps as the relevant Teams-aligned services in its guide.
The affected ACS capabilities include:
- Voice and Video Calling SDK
- Call Recording
- Closed Captions
- Call Automation
The Calling SDK illustrates the boundary. Microsoft says existing calling workloads continue through September 30, 2028, while support after that date requires a supported Teams-aligned scenario. The migration table identifies Teams Meeting Interoperability and says an applicable Teams licence is required. That preserves a supported route for some calling applications, while changing the environment in which those applications operate.
Recording, captions, and automation have their own eligibility conditions. A Teams-aligned integration does not establish feature parity for every ACS capability. Microsoft says recording remains supported only for documented eligible Teams scenarios, captions depend on SDK capabilities and meeting or calling policies, and Call Automation continues after the retirement date only for capabilities documented for eligible Teams scenarios. Each workload needs a feature-level check before anyone treats the Calling SDK as a complete continuation.
Microsoft also warns that supported services may introduce additional service costs, licensing costs, or both. The guide gives no universal per-user amount. That cost question deserves its own model because a Teams-aligned route can change who must be licensed and how the application is sold.
What remains supported as an integrated solution
Microsoft identifies supported integrated scenarios including Microsoft Teams interoperability, Teams Phone, Teams Phone Extensibility, and Microsoft Foundry Speech. This is the third part of the status map. These references describe supported Microsoft solutions and integrations; they are not a blanket statement that every ACS capability outside the retirement list remains unchanged.
That qualification is important for teams that depend on a surrounding ACS component. A calling workload may have a supported Teams route while its existing UI layer is separately listed for retirement. A speech workflow may remain associated with a supported integrated solution while another communications service in the same product follows a different destination. Read the service entry and the supported-scenario entry together.
The safest interpretation is therefore service-specific:
| ACS status | What it means | Planning implication |
|---|---|---|
| Retired | The service or SDK is permanently removed from Azure after September 30, 2028. | Plan a replacement or a rebuild for that dependency. |
| Breaking change | The capability remains available when used with a supported Teams-aligned service. | Validate the Teams scenario, licensing, policies, and feature coverage. |
| Supported integrated solution | Microsoft identifies the solution or integration as supported. | Confirm that each ACS component your product uses is covered. |
The table classifies each dependency; every retired one still needs its own migration plan. ACS Rooms, for example, is retired, and Microsoft has separately stated that it has no migration path to Teams meetings.
The dates that affect your project
The final retirement date is September 30, 2028. Microsoft says existing ACS resources remain available from the September 2026 notification through that date, subject to the restrictions and support limits described in the guide. Availability during the transition does not mean that retiring services will receive new features or normal product investment.
The earlier operational date is October 23, 2026. Beginning then, Microsoft says it will limit onboarding to and expansion of retiring ACS services. Customers without an ACS resource created before that date will not be able to acquire phone numbers for retiring telephony workloads, including PSTN calling and SMS. Microsoft also says that additional measures limiting expansion of other retiring services may be introduced after the date.
Existing customers should therefore separate three questions. Can the current resource continue operating during the transition? Can the team add new numbers, users, or workload capacity? Will the same architecture remain supported after September 30, 2028? A “yes” to the first question does not answer the other two.
For teams starting a new project, the onboarding restriction is the immediate constraint. For teams with an existing resource, the retirement date is the architectural deadline. Both dates belong in the delivery plan, even when the current application appears stable.
What the retirement costs you
The cost is determined by the dependency you carry forward. A service that retires outright creates replacement work. A capability that continues through a Teams-aligned scenario can add licensing or service charges. A workload directed to Dynamics 365, Microsoft 365, Microsoft Foundry, or a Marketplace partner may move into a different commercial and operational model.
Microsoft’s guide explicitly warns that customers may incur additional service costs, licensing costs, or both. It does not publish a universal per-user price for the surviving ACS scenarios, so this article does not attach a dollar amount to staying supported. The correct calculation needs the actual Teams-aligned scenario, the people or identities covered by it, the service meters involved, and the way your product is delivered to its users.
The economic decision is especially different for an internal application and a product sold to third parties. An internal team can evaluate the licensing model against its own workforce and tenant policies. A software company must also determine whether the required licensing model fits a product whose end users belong to customer organisations. That distinction can change the apparent cost of retaining the Calling SDK, even before engineering work is priced.
The detailed economics belong in the companion analysis of enterprise video pricing and the Teams licensing analysis. The reference decision here is simpler. Do not assume that keeping an ACS API means keeping the same bill.
How to classify your ACS dependency
- List every ACS service and SDK in production. Include communication features that are hidden behind an internal wrapper or shared component. The Web and Mobile UI Library SDKs, for example, may be doing work that product teams do not count as a separate dependency.
- Assign each dependency to Microsoft’s status category. Mark it as retired, breaking-change affected, or part of a supported integrated solution. Do not infer the category from the product’s marketing name.
- Record the required destination. A service may point toward Teams, Dynamics 365, Microsoft 365, Microsoft Foundry, a telephony route, or a Marketplace partner. Capture the specific destination named for that workload.
- Test the product boundary. Check identity, tenant policy, permissions, SDK support, recording or caption behaviour, call state, and administration. A supported destination can still require product changes.
- Model the commercial change. Include new licensing and service costs where Microsoft says they may apply. Use the actual scenario rather than a generic Teams price.
- Set the delivery order around the dates. Treat October 23, 2026 as the onboarding and expansion checkpoint for retiring services, and September 30, 2028 as the end of availability for the retired category.
If the inventory contains Rooms or either UI Library SDK, the work is a rebuild of that dependency and deserves its own technical plan. If it contains the Calling SDK, the work begins with Teams-scenario eligibility and licensing. If it contains Email, SMS, WhatsApp, Chat, Job Router, Direct Routing, or Number Management, follow the destination Microsoft documents for that service rather than assuming a common Teams migration.
Bottom Line
Azure Communication Services is retiring as a standalone offering on September 30, 2028. The outcome varies by dependency: some services disappear, some continue only through supported Teams-aligned scenarios, and some workloads have destinations in Microsoft 365, Dynamics 365, Microsoft Foundry, telephony products, or the partner marketplace.
Start with a service-by-service inventory and price the route that Microsoft actually supports. The October 23, 2026 onboarding restriction makes that work an active planning task for new and expanding workloads.
What's Next
Rooms is one of the clearest examples of why the status map needs to be read service by service. The ACS Rooms analysis explains what Microsoft’s lack-of-migration-path statement means for a product built on Rooms.
For the broader engineering question of what changes when a communications dependency moves, see the guide to provider acquisition and shutdown risk.
FAQs
Is Azure Communication Services shutting down completely?
Microsoft is retiring ACS as a standalone offering on September 30, 2028. Some services are retired outright, while some capabilities continue only when used with supported Teams-aligned services or other documented integrated solutions.
What Azure Communication Services products are being retired?
Microsoft lists ACS Email, SMS, Advanced Messaging with WhatsApp, Chat, Chat for Teams Meeting Interop, Rooms, Number Management Direct Offer, Direct Routing, Job Router, and the Web and Mobile UI Library SDKs for retirement. They are scheduled to become unavailable after September 30, 2028 under Microsoft’s retirement guide.
Does the ACS Calling SDK survive?
The Voice and Video Calling SDK is classified as a breaking change rather than an outright retirement. Existing workloads continue through September 30, 2028, while continued support after that requires a supported Teams-aligned scenario and an applicable Teams licence.
What happens to ACS Call Recording and captions?
Call Recording and closed captions continue only in eligible, documented Teams scenarios after the retirement date. Microsoft says eligibility does not guarantee feature parity, and captions also depend on SDK capabilities, licensing, and meeting or calling policies.
Can a new customer still start using retiring ACS services?
Microsoft says it will begin limiting onboarding and expansion of retiring services on October 23, 2026. Customers without an ACS resource created before that date cannot acquire phone numbers for retiring telephony workloads such as PSTN calling and SMS, and Microsoft may introduce further restrictions on expansion.
Will staying on ACS cost more after the retirement announcement?
It may. Microsoft warns that supported services can involve additional service costs, licensing costs, or both, but its retirement guide does not provide a universal per-user amount. The cost depends on the Teams-aligned scenario or alternative destination, the users and identities involved, and the services your application continues to consume.
Is every ACS workload moving to Microsoft Teams?
No single Teams mapping covers the ACS portfolio. Microsoft documents Teams-aligned continuation for selected capabilities, while other workloads point toward Microsoft 365, Dynamics 365, Microsoft Foundry, telephony products, or Marketplace partners.
