Azure Communication Services SMS Retirement: What It Means for Microsoft Teams Texting

Azure Communication Services SMS is being retired. On September 23, 2026, Microsoft announced that Azure Communication Services (ACS) will retire as a standalone offering on September 30, 2028, and its retirement and breaking changes guide lists ACS SMS, ACS Direct Routing, and ACS phone numbers (Direct Offer) among the services that will no longer be available after that date.

The first deadline is much closer. Beginning October 23, 2026, Microsoft starts limiting onboarding: tenants that have not received ACS phone numbers before that date will not be able to buy new ones for PSTN calling or SMS.

If your business texts customers through an app or workflow built on ACS, or runs calls over ACS Direct Routing, this guide covers what retires, what survives inside Teams, why native microsoft teams sms is not a drop-in replacement, and how to plan the move.

What Microsoft Announced and When

Microsoft’s stated reason is strategic: it will “prioritize deeply integrated communication experiences within Microsoft platforms, specifically Teams, Dynamics 365, and Azure, while working with leading Communications Platform as a Service (CPaaS) providers to fill gaps.” In plain terms, ACS stops being a general-purpose texting and calling API, and Microsoft points standalone messaging customers to partners.

The dates that matter:

Existing customers are not cut off yet. Microsoft says tenants granted phone numbers before October 23, 2026 continue to function and can purchase additional numbers during the retirement period, and existing SLAs remain in place. Microsoft also warns that more measures to limit expansion of retiring services can be introduced at any time after October 23, 2026, so it recommends planning the migration now rather than waiting for 2028.

Which ACS Services Retire and Which Survive in Teams

Microsoft splits ACS into two groups. Retired services are removed entirely. Services with breaking changes stay available after September 30, 2028, but only when used with a supported Teams-aligned service such as Teams Phone or Teams Phone Extensibility, and only on new major SDK versions.

The pattern is clear. Voice that runs through Teams Phone has a future inside Microsoft. Standalone texting does not. In the guide’s migration table, SMS is the one channel with no Microsoft alternative listed at all. The only options named are third-party partners (Blip, Infobip, and Telesign). For Dynamics 365 Contact Center, Microsoft’s migration article names SMS through Twilio or Infobip as the supported replacements.

ACS SMS: Numbers, Short Codes, 10DLC, and Porting

ACS SMS supports toll-free numbers, short codes, 10DLC, mobile long codes, and alphanumeric sender IDs, with one-way and two-way messaging. Microsoft now lists its availability as “maintenance mode only.” Here is what the guide says about each piece:

• New numbers. You can acquire new ACS SMS numbers only if you are an existing customer with ACS resources that already have ACS phone numbers. On new ACS resources, the Get phone number option is still visible in the Azure portal but greyed out.
• Short codes. Existing short codes keep working through the retirement period and can be ported to another provider. Short code registration is no longer available for new ACS resources.
• Toll-free verification. Microsoft says there are no known plans to change the current bulk verification process.
• 10DLC. Microsoft has not published a migration path for moving existing 10DLC campaigns and campaign branding from ACS to Microsoft Teams.
• Porting out. You can port ACS numbers, including short codes, to another provider using that provider’s port-in process, usually with a Letter of Authorization. Microsoft warns that moving ACS numbers to another provider requires re-verification with an SMS aggregator and might cause downtime.
• Cleanup. Remove ACS phone numbers before you delete an ACS resource. Otherwise charges can continue on orphaned numbers, and fixing that requires a support ticket.

That 10DLC line is the one Teams admins should notice. Your ACS Brand and Campaign approvals do not carry over to Teams, and verification status after a port depends on the receiving provider’s policies. Budget time for re-registration.

ACS Direct Routing and PSTN: The Teams Phone Migration Path

Calling has a clearer path than texting. Microsoft maps ACS PSTN (Direct Offer) to Teams Phone Extensibility, Teams Calling Plan, Teams Direct Routing, or Operator Connect, and maps ACS Direct Routing to Teams Phone Extensibility or Teams Direct Routing. All of these require Teams and Teams Phone licenses. Microsoft’s Direct Routing migration guide also covers moving to Operator Connect if you want a carrier to manage PSTN for you.

A few details from that guide save real time:

• Licensing changes. ACS Direct Routing bills usage to an Azure resource. Teams Direct Routing and Operator Connect require a Teams Phone license for each user (included in E5 or sold as an add-on). Resource accounts for call queues and auto attendants use the free Teams Phone Resource Account license.
• One FQDN, one platform. You cannot register the same SBC FQDN on ACS and Teams at the same time. For a coexistence period, add an alias FQDN for the new Teams trunk and make sure the SBC certificate covers both names.
• Same Microsoft endpoints. Teams Direct Routing uses sip.pstnhub.microsoft.com, sip2.pstnhub.microsoft.com, and sip3.pstnhub.microsoft.com, the same signaling FQDNs ACS Direct Routing already uses.
• Test before you cut over. Assign a noncritical number to a test user on the new Teams trunk, verify inbound, outbound, and emergency calling, then move production ranges and remove the trunk from ACS.

To find what you actually run, Microsoft points to Azure Advisor > Service Retirement in the Azure portal, which lists affected resources and exports them to CSV.

Why Native Teams SMS Is Not a Drop-In Replacement

It is tempting to assume that if ACS texting goes away, you can move those conversations to Teams’ built-in SMS. For most ACS workloads, you cannot.

Microsoft’s SMS planning guide limits native Teams SMS to Calling Plan numbers in the United States (including Puerto Rico) and Canada, for users licensed with Teams, Teams Phone, and a Calling Plan. Compare that with what ACS SMS customers typically use:

Of the sender types ACS SMS customers rely on, only the 10-digit long code has a native Teams equivalent, and only on a Calling Plan number. Numbers on Operator Connect or Direct Routing, which is exactly where ACS Direct Routing customers will land, never get the Enable SMS option. Numbers on resource accounts, such as a main line on an auto attendant or call queue, show SMS as Not available. And where native SMS does work, it is plain 1:1 texting with no MMS or group threads, as we cover in native Teams SMS limits.

Native setup also takes time. You need Brand and Campaign approval before any number can be enabled for SMS, campaigns allow a maximum of four submissions, and Microsoft’s Campaign setup page says rejected Brand and Campaign applications may take 4 to 6 weeks to process because of request volume.

How to Keep Texting From Your Teams Numbers

Two years sounds like plenty of runway. But the number purchase freeze starts October 23, 2026, re-verification and porting can take weeks, and Microsoft has said more restrictions may follow. A practical plan looks like this:

1. Inventory. Use Azure Advisor’s Service Retirement view to list every ACS resource, then map each phone number to its sender type (10DLC, toll-free, or short code) and the app or workflow that uses it.
2. Split voice from messaging. Move ACS Direct Routing and PSTN calling onto Teams Phone through Direct Routing, Operator Connect, or Calling Plans. That half of the migration has a Microsoft path.
3. Pick a messaging home before you port. Decide which numbers should text from Teams and which belong in a separate application-to-person platform. Confirm 10DLC, toll-free, and short code re-verification requirements with the receiving provider.
4. Export what you need. Microsoft says chat messages, recordings, and telemetry can be exported, and that supporting data for retired services is decommissioned after the retirement date.

For teams that want customer texting to live where they already work, Clerk Chat adds SMS, MMS, RCS, and WhatsApp to your existing Teams phone numbers, including Operator Connect and Direct Routing numbers that native Teams SMS skips. Clerk Chat is also a certified Operator Connect partner, so the calling side of an ACS exit and the texting side can land on the same Teams numbers, with 10DLC registration handled by our team.

Frequently Asked Questions

Is Azure Communication Services SMS being retired?

Yes. Microsoft’s retirement guide lists ACS SMS as a retired service. It remains supported in maintenance mode until September 30, 2028, and after that date it will not be available. Microsoft announced the retirement on September 23, 2026.

Can I still buy Azure Communication Services phone numbers?

Only if your tenant already had ACS phone numbers before October 23, 2026. Those tenants can keep buying additional numbers during the retirement period. Tenants without ACS numbers before that date cannot purchase new numbers for PSTN calling or SMS, and new short code registrations are no longer available on new ACS resources.

What does Microsoft recommend instead of ACS SMS?

Microsoft does not list a Microsoft alternative for standalone SMS. Its retirement guide names third-party partners Blip, Infobip, and Telesign through Microsoft Marketplace. For Dynamics 365 Contact Center, Microsoft names SMS through Twilio or Infobip as the supported replacements.

Can I move my ACS 10DLC campaigns to Microsoft Teams?

Not today. Microsoft says it has not published a migration path for moving existing 10DLC campaigns and campaign branding from ACS to Microsoft Teams. Plan for new Brand and Campaign registration wherever those numbers end up.

Can I port ACS phone numbers out?

Yes. You can port ACS numbers, including short codes, to another provider using that provider’s port-in process, usually with a Letter of Authorization. Microsoft warns that re-verification with an SMS aggregator is required and might cause downtime, so schedule ports in stages.

What replaces ACS Direct Routing?

Microsoft points ACS Direct Routing customers to Teams Direct Routing or Teams Phone Extensibility, and its migration guide also covers moving to Operator Connect. Each option requires Teams Phone licenses for users, and you cannot register the same SBC FQDN on ACS and Teams at the same time.

Does the ACS retirement affect Teams Phone?

No. Microsoft says Teams Phone, Teams Phone Extensibility, and Teams interop are supported scenarios. ACS calling features such as Call Automation and Call Recording continue after 2028 only when used with a Teams-aligned service and updated SDK versions.

The Bottom Line

Microsoft is folding ACS voice into Teams Phone and leaving standalone texting to partners. ACS SMS, ACS Direct Routing, and ACS phone numbers retire on September 30, 2028, and the purchase freeze for tenants without ACS numbers starts October 23, 2026. Calling has a defined path to Teams Phone Direct Routing, Operator Connect, or Calling Plans. Texting does not, and native Teams SMS only covers 1:1 messages on US and Canadian Calling Plan numbers.

If your customers text the numbers your team answers in Teams, plan the messaging side of the move now. See the Microsoft Teams integration or book a demo and we will map which of your ACS numbers move to Teams Phone, which need to text, and how to keep both on the same line.