Teams Phone Configurator — Phone Number Management for Microsoft Teams

Teams Phone Configurator is a self-hosted web application for managing phone numbers in Microsoft Teams Phone. It replaces the spreadsheet that records which number belongs to whom, and the PowerShell runbook that assigns it. Number inventory, one-screen provisioning, and per-site policy assignment run from a single dashboard, secured by your existing Microsoft Entra ID sign-in.

The Problem It Solves

Every company running telephony on Microsoft Teams owns blocks of phone numbers — a range per office, bought from a local operator. In almost every one of them, the record of which number belongs to whom lives in a spreadsheet maintained by hand. Assigning a number to a new employee means finding that document, picking a number that looks free, opening a PowerShell console, and running a site-specific sequence of commands from an internal runbook. Offboarding means remembering to do the same in reverse. Every manual assignment costs 10–15 minutes of engineer time and sits one typo away from a misrouted number.

What It Does

• Number inventory: all ranges organised by office location, with live status for every number (free or assigned) and utilisation per range and per location.
• One-screen provisioning: search the employee in your directory, see whether they hold a Teams Phone licence before anything is changed, pick a number or take the next free one, and assign. The change lands in Microsoft Teams in seconds.
• Site policies applied automatically: each location carries its own voice routing, calling policies and dial plans, applied in order on every assignment — the same way for every admin.
• Offboarding in one action: remove what the departing employee holds from Teams and from the inventory at once; the number returns to the free pool immediately.
• CSV import and export: export a location's assignments for reporting, or import the numbers you already assigned over the years.
• Audit trail: who assigned what to whom, when, and whether it succeeded — recorded with configurable retention.
• REST API: everything the UI does is available to automation, for HR-driven onboarding, ITSM integration and reporting.

What It Deliberately Does Not Do

The application manages the lifecycle of numbers and users, not your telephony infrastructure. Operators, session border controllers and the policy definitions themselves stay in the Microsoft Teams admin center, under the control of your telephony engineers — the app only applies what they defined. That separation of duties is what makes the tool safe to hand to a service desk, which can then provision numbers without holding PowerShell or Teams admin portal access. It complements the wider IT governance and compliance controls in your tenant.

Who It Is For

IT teams running Microsoft Teams Phone across multiple offices — Direct Routing, Operator Connect or Calling Plans, typically a few hundred to tens of thousands of numbers — where number administration today depends on documents, tribal knowledge, and PowerShell access for everyone who provisions.

Architecture and Security

The application is built on .NET 10 and Blazor Server with SQL Server persistence (the free Express edition is sufficient). All telephony writes go through the Microsoft Graph number-management API using app-only authentication — no PowerShell, no module dependencies, no interactive sessions. Users sign in with Microsoft Entra ID (OpenID Connect) and access is gated by app roles, Telephony Admin and Viewer; there are no local accounts and no stored passwords. The service principal holds only the Graph permissions it needs, all admin-consented. These are the same cloud security principles we apply across customer tenants.

Deployment and Cost

The app ships as a single Docker container alongside SQL Server Express, so it runs on any Docker host — including a VM you already have — at effectively zero infrastructure cost. The same container on Azure Container Apps runs in the low single-digit euros per month at this workload. Configuration is entirely environment variables, so one image serves every environment. There is no per-user licensing and nothing to install on client machines. Setup requires one Entra app registration and takes about 15 minutes.

Teams Phone Configurator can run on your own infrastructure, or IDE Solutions can deploy and operate it for you alongside our Microsoft 365 services and managed Azure cloud. Contact us to book a demo. For tenant-wide accountability over mailboxes, Teams and service accounts, see our Ownership Registry.