Migrating from Legacy Mitel to Microsoft Teams Voice Across a Multi-Site Trust

As with many education environments, Microsoft is central to the way this multi-academy trust operates day-to-day. Meetings, instant messaging, channels and team collaboration had all moved into Teams long before voice was looked at, making voice the one part of the communication stack that still sat in isolation.

The legacy Mitel system underpinning that voice estate had become both unstable and expensive, costing a significant amount to maintain across services and licensing, while no longer providing the reliability the trust needed. At the same time, the system had become a siloed application that wasn't being used in the way it had originally been designed. Modern educational work simply doesn't follow the pattern that legacy phone systems were built for, and the gap between the technology and the way staff actually worked had widened to the point that change was overdue.

Beyond the operational and cost pressures, the trust needed to understand whether Teams Voice was genuinely the right answer for its environment, not just the obvious one. With circa 600 users across multiple sites, the move had to be designed around how voice was actually being used, not assumed. 

Formation Tech were engaged initially to help the trust understand how the current system was being used, using a standard assessment approach that produces a detailed document with recommendations on what extensions are used for, who has what, what groups exist, and what can be translated cleanly into Teams Voice. The starting point of the engagement was a clear, objective answer to a simple question: based on how this trust actually operates, is Teams Voice the most suitable solution? The strategic document that came out of this work formed the first pillar of the design process for the move.

Having established that Teams Voice was the right fit, Formation Tech were engaged to configure and deploy the solution. The new voice environment was built within the trust's Microsoft tenants without any impact to either the existing Microsoft services or the live Mitel operation, meaning the trust could see the new platform take shape alongside the old one rather than in place of it. By connecting in a dummy trunk and phone number, Formation Tech were then able to help the customer test and validate groups, functionality and the full user experience well before any cut-over was required.

A key design decision concerned the existing carrier and phone numbers. Moving to Microsoft Teams Voice does not have to require an organisation to port its numbers to Microsoft, in fact, the significant majority of Teams users connect via a third-party carrier. Formation Tech retained the trust's existing numbers and phone details with the existing carrier, while seamlessly migrarting the billing relationship to Formation Tech. This meant that, at the point the trust was happy with the testing, features and functions, cut-over was a simple matter of repointing the IP address to the new solution, avoiding a disruptive number port from one carrier to another.

To support the trust's specific operational needs, Formation Tech also deployed an enhanced reception console solution. Reception handles the majority of calls in a school environment, and while a native console is provided by Microsoft, Formation Tech's solution mimics and replicates the historical flat-bed consoles that receptionists are used to, preserving the working pattern that reception staff have built up over years rather than forcing a change for the sake of it.

Alongside the platform itself, Formation Tech provided a call logging solution to meet certain regulatory requirements specific to the education sector. While not native to Microsoft Teams, the logging and reporting function helps the trust manage the key requirements mandated by the relevant educational regulator.

Following deployment, the trust's voice estate now sits within the same Teams environment that already powered the rest of its communication, closing the gap between voice and the rest of the day-to-day toolset. The number of physical handsets across the school estate was reduced drastically, leaving handsets only where they genuinely matter: in key safeguarding locations such as sports halls and kitchens. Teachers can now both receive and make calls to and from parents in a place of their choosing, rather than having to go to a dedicated room, a meaningful change in how communication actually fits into the working day.

Commercially, the engagement was delivered on a net neutral basis. The combination of the educational pricing available for Microsoft Voice and the high cost of supporting and licensing the previous Mitel platform meant that the trust gained a modern, unified communications capability without an increase in spend.

The migration itself was carried out without disruption to the live Microsoft or Mitel environments, with full testing of the new platform completed before any cut-over took place. With the legacy Mitel system retired, the enhanced reception console in place, and regulatory call logging covered, the trust now operates a single, unified communications estate underpinned by Microsoft, supporting the way modern education actually works, across every site within the group.