SIX, the Swiss financial infrastructure operator, has completed a 12-month migration of 1,700 voice seats to Microsoft Teams, shedding decades-old PBX hardware and a legacy call recording system that couldn’t meet modern compliance demands. The project, finished in mid-2026, is a real-world blueprint for financial services firms, healthcare providers, and anyone else subject to strict voice retention rules—proving that cloud calling can be both flexible and audit-ready.
What actually changed
SIX replaced a mixed bag of Alcatel PBX systems, legacy call center products, and a NICE recording platform with two components that slot directly into Microsoft Teams: Luware Nimbus for contact-center routing and Luware Recording for compliance capture. The deployment covers 25 sites across Switzerland and Spain and centralizes all SIP trunks into a single interconnection, eliminating the need for local telephony at each branch.
In practice, the new architecture looks like this:
- Teams acts as the collaboration layer and softphone client.
- Nimbus handles advanced routing, queues, and agent functions that go beyond what Teams natively offers.
- Luware Recording—built on technology from Verint—grabs every workplace call and stores it with metadata so compliance teams can search, retrieve, and audit recordings for up to a decade.
Andrea Panarese, SIX’s head of voice services, told Diginomica that the project moved 1,700 seats across 609 services without disrupting daily operations. The old world was location-bound: if a branch needed voice, it needed its own PBX. Now, the same centralized SIP trunk serves all users, and service owners can manage team memberships and pull reports themselves rather than filing ad hoc requests to an internal support desk.
What it means for you
For IT admins in regulated industries
If your organization falls under FINMA, MiFID II, PCI DSS, or any rule that says you must record and keep calls for years, the SIX case is a direct parallel. The key takeaway: native Teams compliance recording isn’t enough. You will almost certainly need a certified third-party recorder that integrates via the Teams compliance recording APIs. Luware Recording (based on Verint) is one option; other players like NICE, Ascend (from AudioCodes), and Dubber offer similar add-ons. The difference here is that SIX ran a full contact center on top of Teams using a single vendor for both routing and recording, which simplified procurement and integration.
Admins should note the emphasis on centralized SIP. SIX moved all telephony interconnection to one point. For a small outfit, that might mean a single Session Border Controller (SBC) for Direct Routing; for a larger one, it could mean Operator Connect or a set of redundant trunks. The architecture choice matters because it determines how call data flows and where you can tap in for recording. SIX’s design also eliminated local PBX dependencies, which cuts hardware costs and lets business processes span countries without telephony barriers.
For everyday Teams users
Most end users won’t see anything different in their daily workflow—and that’s the point. Panarese highlighted that moving to the cloud put everyone on the same platform. A trader in Zurich and a compliance officer in Madrid use the same Teams interface. Self-service reporting means a business manager can pull call records without involving IT, which is a quality-of-life upgrade for anyone who routinely needs call data.
But there’s a hidden benefit: resilience. A centralized cloud setup with Teams means if a physical office goes dark, calls can be routed elsewhere instantly. That’s not new tech, but in a world where Teams is already the collaboration hub, tying voice to the same fabric makes disaster recovery simpler.
For developers and integrators
Luware Recording uses Verint technology, which hints at a wider ecosystem of AI-powered analytics that can be layered on top later. SIX says AI is on the roadmap—likely for interactive voice response (IVR) and analyzing the recording archive. If you’re building or evaluating voice solutions for Teams, look for recording platforms that expose APIs for analytics and AI, because the business will ask for that next.
How we got here
The migration didn’t start with Teams. SIX had already moved part of its voice estate to Skype for Business as an interim step. When Microsoft announced in January 2024 that Skype would be retired, the clock started ticking. Panarese’s team knew they had to finish the jump to Teams, but they also needed to solve the compliance puzzle that Skype for Business alone couldn’t address.
Their previous environment combined Alcatel PBX hardware, call-center software, and a NICE recording system that was aging. For a company that handles exchange, securities, and payments infrastructure—where a single disputed voice record can be pivotal in a legal proceeding—a platform that struggled with 10-year retention was a business risk.
The evaluation process, according to Panarese, favored Luware because of tight Teams integration, automatic authentication, and a simpler technical implementation compared to other solutions. Price was also a factor. The 12-month rollout moved carefully from simple use cases to complex one, ensuring continuity.
Meanwhile, Microsoft’s push to make Teams a full-fledged phone system has accelerated. Teams Phone now includes features like shared calling, auto attendants, call queues, and advanced compliance recording APIs. But it’s still a platform play: Microsoft relies on partners like Luware, AudioCodes, and others to supply the pieces that regulated enterprises need. SIX’s project is a case study in how that partnership model works in the most demanding environments.
What to do now
If your organization is staring down a legacy PBX replacement or a Skype-for-Business-to-Teams migration with compliance obligations, here’s a distilled action plan from the SIX experience:
- Inventory your regulatory requirements. Know exactly how long you must keep recordings (10 years in SIX’s case), which calls are in scope, and what metadata you need for retrieval. Swiss regulations (FINMA, FinfraG) plus PCI DSS drove SIX’s design; your rules may differ.
- Don’t assume Teams alone can do it. Teams Phone handles calling well, but its native compliance recording is limited. Research certified third-party recorders that use the Teams compliance recording APIs. Look for solutions that can also handle contact-center routing if you need agent queues and skills-based routing.
- Plan your telephony architecture. Decide between Direct Routing (you host an SBC), Operator Connect (carrier-managed), or a mix. SIX centralized SIP trunks to reduce local hardware. That works well if your network and carrier can support it. Test failover and quality of service before moving a single production seat.
- Phase the migration by complexity. Start with straightforward users who just need calling, then tackle contact-center agents and compliance recording. SIX began with simple use cases and built from there. Each phase should validate that recordings are being captured and stored correctly.
- Empower service owners. One soft benefit SIX highlighted: giving business teams self-service access to membership management and reports. Plan to delegate roles in the Teams admin center or via the recording tool so that IT isn’t a bottleneck for routine changes.
- Pre-wire for AI. Even if you’re not deploying AI analytics yet, choose a recording platform that can support it later. Ask vendors about APIs, transcription capabilities, and integration with tools like Copilot for Microsoft 365 or third-party AI services.
A final note on costs: SIX didn’t share a euro figure, and Panarese characterized voice as “not value creation” but “business-critical”—a sentiment common in regulated infrastructure. Expect that cloud voice might not pay for itself in line-item savings as much as in risk reduction and operational flexibility.
What’s next
AI is the next frontier for SIX, but it’s not built yet. The company is exploring how to apply AI to IVR and to its recording archive for better customer service and behavioral analysis. For Windows and Microsoft 365 watchers, that points to a future where Teams call data becomes fuel for compliance AI, sentiment analysis, and automated supervision. In the short term, SIX’s migration proves that even the most heavily regulated enterprises can move off PBX without breaking compliance. The tools are ready; the blueprint is public.