Azure Communication Services Retires Email, SMS and Chat in 2028

Microsoft ends Azure Communication Services as a standalone offering on September 30, 2028​

The notice appeared in the Azure Updates feed on September 24, 2026, and in the ACS "What's new" page on Microsoft Learn under September 2026. That page says Azure Communication Services retires as a standalone offering on September 30, 2028. Some services retire, while others remain available with breaking changes that require migration to supported Teams-aligned scenarios. So far, Microsoft's own documentation is the only public record. No independent outlet has reported the retirement yet. Because this is a first-party announcement of a Microsoft service's lifecycle, the documentation is authoritative on what it announces.

ACS is Azure's developer platform for building communications into your own apps. Microsoft's overview describes it as multichannel communication APIs for adding voice, video, chat, text messaging/SMS, email, and more to all your applications, delivered through REST APIs and client SDKs for JavaScript, iOS, Android and Windows (.NET). It powers customer-facing apps like telehealth video visits, banking support lines, appointment-reminder texts and transactional email. That is why the retirement changes application architecture, not just an Azure portal setting.

A separate retirement and breaking-changes guide on Microsoft Learn spells out the stakes. Developers must update your application by September 30, 2028. After that date, standalone ACS workloads that don't integrate with a supported Teams-aligned service will no longer be supported. The key word is "standalone." A workload built only on ACS, with no Teams, Dynamics 365 or supported Azure tie-in, is exactly what Microsoft is ending.

Eleven ACS services face outright retirement, from Email and SMS to Rooms​

Microsoft sorts every ACS product into one of two categories, and the difference decides how much work you have. In the guide's definitions, a retired service won't be available after September 30, 2028. A breaking-change service remains available, but changes to its functionality or support requirements might require you to modify existing applications.

The September 2026 notice lists these services as retiring:

Microsoft means "retired" literally. Retirement means a service is permanently removed from Azure and isn't available after September 30, 2028. This condition applies even when you use the retired product with other supported services described in this guide. Wrapping ACS SMS or Email in a Teams-integrated solution will not keep it alive. The guide also warns that after September 30, 2028, retired services aren't supported and can't be used. API and SDK calls that depend on retired services may start returning errors.

Two entries stand out. The first is Chat for Teams Meeting interoperability. It is already a Teams-integrated feature, yet it is on the retirement list rather than the breaking-change list, so being Teams-related does not guarantee survival.

The second is Direct Routing. In ACS, this is the feature that uses SIP and session border controllers to connect your own phone carriers and bring your own numbers. Microsoft's Teams Phone extensibility material lists integration with Teams Calling Plans, Direct Routing and Operator Connect as telephony options. It is reasonable to infer that Teams-side telephony is where Microsoft wants these customers to go. However, the notice does not name Teams Direct Routing as the replacement for ACS Direct Routing.

Calling SDK, Call Automation and Call Recording survive with breaking changes​

The second list covers ACS's real-time voice stack. These services remain available after September 30, 2028, but only in a changed form:

• The Voice and Video Calling SDK, used to add calling to browser and native apps, continues with breaking changes.
• Call Diagnostics continues with breaking changes.
• Call Automation, the server-side API for interactive voice response (IVR) and programmable call flows, continues with breaking changes.
• Audio Streaming continues with breaking changes.
• Call Recording continues with breaking changes.
• Closed Captions continues with breaking changes.

For these services, the practical requirement concerns SDK versions. The retirement guide states that if you plan to use an affected service after September 30, 2028, you must update to the latest major version of the SDK. A new major version usually signals API changes that are not backward compatible, so calling teams should plan for code changes and regression testing, not a simple version bump. The published summary does not yet give the specific API differences in each new major version. That gap matters for effort estimates, and teams should track the guide's Impacted Services and SDKs table for updates.

Microsoft is also clear about where the surviving services must run: in Teams-aligned scenarios. An ACS calling app that operates independently of Teams, such as a consumer-to-consumer video product, is the kind of standalone workload the guide says will lose support. A calling app already connected to Teams users, meetings or Teams Phone is closer to where Microsoft wants customers to end up.

The October 23, 2026 sign-up cutoff arrives first​

September 2028 is the headline date, but the first deadline is less than a month away. According to the guide, beginning October 23, 2026, new customers can't sign up for Azure Communication Services retiring services. Customers with an Azure Communication Services resource created before October 23, 2026, can continue using their existing resources and retiring services to support current business workloads during the transition period.

This has a direct effect on anyone evaluating ACS right now. An organization that was about to adopt ACS Email or SMS for a new project has a few weeks before that option closes to newcomers. Even if it gets in before the cutoff, it would be building on a service that disappears in two years. Existing customers keep their resources through the transition period. The guide frames that continuity around supporting "current business workloads", which suggests the transition period is meant for running down existing workloads, not expanding onto retiring services.

Here is the timeline so far:

The published material does not describe any intermediate cutoffs between October 2026 and September 2028, such as throttling or phased feature removal. Treat the two dates above as the only fixed milestones.

Why Microsoft is folding ACS into Teams, Dynamics 365 and Azure​

Microsoft presents the retirement as a strategy change. The guide says the move reflects our evolving strategy to prioritize deeply integrated communication experiences within Microsoft platforms, specifically Teams, Dynamics 365, and Azure, with Microsoft continuing to work alongside partners. ACS has been a general-purpose communications platform for developers, and Microsoft is now narrowing it to a component of its own products.

You can see this direction in earlier ACS releases. In June 2025, Microsoft introduced Teams Phone extensibility in public preview, aimed at Dynamics 365 Contact Center and contact center as a service (CCaaS) ISV solution vendors who want to carry Teams Phone telephony into contact centers. The ACS documentation says that feature is powered by ACS. It relies on Call Automation APIs and the ACS Client SDK, and it lets independent software vendors (ISVs) build on existing Teams Phone plans without adding ACS numbers or ACS Direct Routing. Those are exactly the calling components that survive the retirement with breaking changes. The number and routing components that Teams Phone extensibility made optional are the ones being retired.

That fit helps explain why Microsoft is taking this route. Keep one limit in mind: the Microsoft Learn material shows the direction, but it does not show that Teams Phone extensibility, or any other Teams feature, fully replaces any specific retiring ACS capability. For messaging services like Email, SMS and WhatsApp, the published announcement names no Teams-aligned successor at all.

What this means for ACS developers and IT teams​

Start by auditing which ACS services each of your workloads uses. Every service falls into one of two categories with very different outcomes, and one application can straddle both. For example, a telehealth app that sends SMS appointment reminders, runs video visits on the Calling SDK and uses the Web UI Library carries one retiring dependency, one breaking-change dependency and a second retiring dependency. Each needs its own plan.

Teams whose ACS use is limited to calling features have a code-migration project. They need to reach the latest major SDK versions and connect their workload to a supported Teams-aligned scenario by September 30, 2028. Teams that depend on ACS Email, SMS, WhatsApp, Chat, Rooms, Job Router, ACS phone numbers or ACS Direct Routing have a platform-replacement project. Microsoft's announcement names no drop-in successor for those services, so the choice of replacement falls to you. It is sensible to start that evaluation well before 2028, especially for SMS and email flows that are bound up with phone numbers, sender domains and compliance processes.

Organizations that were only evaluating ACS face a quicker decision. After October 23, 2026, new customers cannot sign up for the retiring services, and anything built on them now would have a two-year lifespan.

• Inventory every ACS resource and record which of the 17 listed services each workload calls. Treat ACS as a set of separate services, not one product.
• Treat Email, SMS, WhatsApp, Chat, Chat for Teams Meeting interoperability, Rooms, Number Management (Direct Offer), Direct Routing, Job Router and both UI Library SDKs as ending on September 30, 2028, even if they run alongside supported services.
• Plan to move the Calling SDK, Call Automation, Call Diagnostics, Audio Streaming, Call Recording and Closed Captions to their latest major SDK versions, and budget for code changes and testing.
• Avoid starting new projects on retiring ACS services. New sign-ups close on October 23, 2026, and existing resources are meant to support current workloads during the transition.
• Watch the Impacted Services and SDKs table in Microsoft's retirement guide and the Azure Updates feed. Microsoft points customers to both for product changes as the transition goes on.

Microsoft has given ACS customers two years and a clear line: calling survives if it runs inside Teams, and almost everything else goes away. The October 23, 2026 sign-up cutoff is the first decision point, closing the retiring services to new customers. For existing customers, the real deadline is September 30, 2028. After that, ACS messaging services and standalone ACS workloads stop working, and the replacement for your SMS and email pipelines is something you will have to choose yourself.