W1M enables secure, compliant collaboration across Microsoft 365 tenants

When W1M Wealth and Investment Management Ltd (W1M) was formed through the merger of London & Capital and Waverton in 2025, it brought together more than £19 billion in assets, over 325 employees, and offices spanning London, Edinburgh, Glasgow, Barcelona, and Barbados. Regulated across the FCA (UK), SEC (US), and CNMV (EU), the newly combined firm operated under significant governance and reporting obligations from day one.

Yet despite operating as a single business, the two legacy firms were still running as independent entities with separate Microsoft tenants. Across their respective Microsoft 365 environments, each had built up its own processes, security setups, and custom system integrations over two decades.

“The biggest challenge was the fragmentation of having multiple systems between two different entities,” says Adnan Uz-Zaman, Head of IT at W1M. “We had duplicate processes, inherited legacy platforms, and limited visibility across departments.”

For Victoria Carroll, Chief Marketing Officer, the greater risk was keeping work consistent. “When people are spread across different systems and versions of documents, there’s always a risk of misalignment, delays, or errors creeping in.”

Bringing together these two intricate technology estates under strict regulatory and operational pressure meant the consolidation had to be carefully managed. Beyond operational alignment, however, the leadership team was equally focused on reinforcing the firm’s long-term risk posture. 

As Chief Operating Officer Michael Allen explains, the goal was clear: “To strengthen our cyber security protocols, improve our overall IT risk profile, and provide a flexible, secure user experience that could evolve with the business (and industry) requirements.”

The transition would therefore need to unify digital environments, standardize controls, and maintain rigorous security throughout building a platform that was secure and compliant by design, operationally resilient, and ready to support future acquisitions.

Ensuring continuity while delivering complex change

From the outset, operational continuity was a critical priority. “The business needed to carry on, regardless of the migration actions,” says Gerhard Hechter, Network and Infrastructure Manager at W1M.

To ensure users experienced little or no interruption to their work, the technical team conducted deep discovery and dependency mapping, engaged business units throughout, and maintained parallel BAU support during a phased cutover.

Adnan Uz-Zaman describes the dual-track workload: “We continued with standard BAU while working in project mode. It was a disruptor during the normal day-to-day, but we had the right team in place.”

The project demanded constant prioritization, rapid issue resolution, and sustained cooperation between the two legacy teams.

Securing cross-tenant collaboration and governance

Although both firms already used Microsoft 365, a breakthrough moment came when Microsoft advised W1M to adopt the multitenant organization (MTO) model. With detailed consolidation planning still underway, this enabled secure collaboration across tenants.

“Multitenant organization went GA two months before our go live, allowing staff to collaborate while relying on our existing security parameters,” says Uz-Zaman.

Staff could share Microsoft Teams channels, access SharePoint sites, and engage with shared data while the two organizations technically remained separate. This removed the need for temporary site-to-site VPNs, while giving the organization time to align governance, identity, and security models before final cutover.

During this period, W1M elevated its security posture across both tenants. Each legacy company had previously used Microsoft security tools, but in different ways. The team standardized and strengthened controls using Defender for Endpoint, Defender for Cloud, Defender for Identity, Sentinel, Purview, Intune, and Entra ID, supported by conditional access, MFA, and data-loss-prevention policies applied consistently across environments. Meanwhile, around 50 legacy systems and services were retired.

“Being on the same Microsoft stack made it easier to validate that the platforms were secure and compliant before any migration work started,” says Hechter.

This shared security foundation extended beyond IT readiness. “Our clients expect confidentiality and resilience, and Microsoft’s security tools absolutely reinforce confidence,” says Carroll. “Strong governance and a trusted environment reduce risk and manual workarounds, improving client outcomes.”

Delivering a zero-downtime migration and modern architecture

With cross-tenant collaboration established and security controls aligned, W1M executed the full tenant consolidation. Over seven months, up to 150 devices were standardized, with around 200 user and shared mailboxes migrated, and 10 TB of data moved.

The migration was delivered internally with zero downtime, supported by targeted architectural guidance from Microsoft. “Users thought we’d just done a small migration—and that’s because they weren’t negatively impacted. That’s what success looks like,” says Hechter.

The consolidation also enabled broader modernization. W1M standardized on Microsoft Surface devices to create a manageable hardware baseline. Identity and access were rationalized, consolidating single sign-on across third-party services while ensuring continuity during migration.

The organization retired on-premises file servers, adopted SharePoint and OneDrive at scale, and replaced MFA based VPN logins with Always On VPN.

“There was a clear drop in service desk requests once we moved to a unified, modern setup,” says Uz-Zaman. 

Strengthening partnership and collaboration

In its oversight role, Microsoft confirmed MTO as the right strategy, validated security and identity architecture, and reduced uncertainty during consolidation planning.

“Microsoft has always directed us on the right path. Their validation was invaluable,” says Uz-Zaman.

Beyond technology, the program strengthened working relationships and clarified W1M’s external presence. During the rebrand rollout, Marketing needed to move large volumes of assets quickly between teams and partners.

In the unified environment, version control and shared workspaces removed friction and reduced rework. “Shared libraries gave quicker prompts on changes or permissions, helping us avoid outdated assets or incorrect versions reaching clients,” says Carroll.

Enabling AI adoption and creating a blueprint for growth

Following tenant consolidation, W1M expanded its adoption of Microsoft 365 Copilot, moving from a 25-user pilot to a structured rollout for 300 staff, supported by role-specific enablement.

“We don’t just provide the license—we speak to Copilot champions, understand a day in the life of the role, and show where Copilot can add value,” explains Uz-Zaman.

Early use cases included summarizing complex documents, automating data preparation, and accelerating research workflows. The program is now a multi-year initiative aimed at embedding AI into everyday work.

With AI adoption rising across functions, the strategic dimension of the Microsoft relationship becomes increasingly important. “As the introduction of Copilot and use of AI expands, our relationship with Microsoft will be critical in supporting our long-term business objectives,” says Allen.

Crucially, the consolidation has created a repeatable blueprint for future mergers and acquisitions:

•           A Microsoft-first cloud architecture
•           A unified security and governance model
•           Standardized devices and identity
•           Cloud-based collaboration
•           Structured AI enablement

“Since the migration, I see our approach as a lot more aligned, consistent, and resilient. It has given us a clear and repeatable blueprint that we can use for future acquisitions,” says Uz-Zaman. 

Through disciplined planning and strong vendor partnership, W1M consolidated two independent infrastructures into a single modern environment, with zero downtime and no material business disruption—ready for its next phase of growth.

Discover more about W1M on LinkedIn.