Nimbus uses bots to initiate and monitor (safe) transfers and create call conferences. If Microsoft decides to pull through with this change by September 30, 2025, all Nimbus transfers and consultation calls will be blocked and fail without any possible workaround or error handling.

Topic: Microsoft announced changes to PSTN license checks for bots. From the Blog Post of Microsoft:

As part of Microsoft’s feature parity with Teams Phone extensibility, we’re announcing the enforcement of Phone System license checks for Bot-initiated transfers to Teams users. This current gap in our systems will be addressed in September 2025.

Microsoft Teams requires that Teams users behind applications such as queue applications require a phone system license and the user to be Enterprise Voice Enabled. We’re aligning the Microsoft Graph API with that requirement.  

What is the change?
Effective September 30, 2025:

• Teams users will still have the option to transfer calls to other Teams users manually even if they don’t have a PSTN phone system license.
• Bot-initiated transfers and add participant requests to non-phone system enabled users will be blocked.  

🧭 What is the Impact for Luware Nimbus Users?

• Transfers Within Nimbus: Transfers to users without a Teams Phone license will no longer work. This includes internal transfers between agents or service users.
• Supervision Features: Supervisors must have a Teams Phone license to monitor or intervene in calls. Without it, supervision capabilities are disabled.
•  Workflow Transfers: Any transfer initiated from a Nimbus workflow to a user lacking the appropriate license will fail. This disrupts automated routing logic and impacts service continuity.
•  Attendant Console Transfers: Transfers via the Attendant Console to unlicensed users are blocked. This affects manual call handling and redirection.

✅To ensure uninterrupted service: 

This change mandates the use of a PSTN License on all Users you either transfer to or start a consultation call with.

• Audit User Licenses: Verify that all users involved in call handling, transfers, and supervision have the Microsoft Teams Phone license assigned.
• Update Workflows: Adjust workflows to route calls only to licensed users. This includes adjusting any Distribution Policies and Agent Service Settings for Agents with the according skills and responsibilities.
• Train Supervisors: Ensure supervisors understand the licensing requirements and have the necessary access.
• Monitor License Status: Implement checks or alerts to identify users without valid licenses.

Nimbus uses bots to initiate and monitor conferences well as monitor and report any Outbound Call calls and Call On Behalf of a Nimbus Service. Any transfer scenario also requires the Nimbus bot to take calls back safely.

This includes:

• CQ agents making calls on behalf of a Resource Account (RA)
• Callback scenarios configured in Call Queues
• Auto Attendants transferring calls externally
• Calls initiated via Graph API or Phone System extensibility

🧭 What is the Impact for Luware Nimbus Users?

For customers using Microsoft Telephony exclusively and leveraging Call On Behalf features via Luware Nimbus, this change means:

• You must replace existing Calling Plan licenses on resource accounts with PAYG (Pay-as-you-go) licenses.
• Failure to do so will result in service interruptions for Outbound Calls initiated by Nimbus services, e.g. within either Attendant Console, Workflows in Contact Center routing.
• As highlighted in internal discussions with Microsoft, this enforcement aims to curb misuse but inadvertently affects legitimate use cases like those supported by Luware Nimbus.

✅To ensure uninterrupted service: We urgently recommend for Customers begin transitioning to PAYG licenses well before November 1st to avoid last-minute disruptions.

1. Review all resource accounts configured for outbound PSTN calls.
2. Assign PAYG Calling Plan licenses to these accounts via the Microsoft 365 Admin Center.
3. Validate license coverage for all users and services involved in call transfers.
4. Consider setting up Communication Credits to fund PAYG usage if needed.

📞 Need Help?

If you’re unsure how this change affects your setup or need assistance updating your licensing, please reach out to your Luware Customer Success Manager or contact our Support Team.