Teaming up to work smarter, move faster and deliver more.

Not just a Microsoft 365 migration — a blueprint for modern work

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  • June 26, 2025

At PwC, sometimes we’re our own client. We led one of the largest Microsoft 365 transformations — navigating global regulations, scaling AI at speed and inspiring new ways of working. But we didn’t just migrate — we modernized. It’s part of our commitment to lead in tech and transformation, within PwC and alongside our clients, so our teams can deliver smarter, move faster and focus on outcomes — not obstacles.

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CLIENT

INDUSTRY

Professional services

FEATURING

Microsoft

15+

petabytes of data securely migrated

25x

larger than the average migration, with over 500,000 mailboxes migrated

$25M+

savings globally through tech consolidation

Trust pictogram

A modern foundation for secure, compliant and trusted work — across data, AI and every client interaction

SITUATION

Borderless collaboration. Region specific precision.

At PwC, we were already in a cloud network— but capacity alone wasn’t enough. Supporting 370,000 people across 149 countries meant working within a patchwork of compliance laws, legacy tools and region-specific priorities. Collaboration could be inconsistent. Innovation was getting harder to scale. Client expectations were rising. We saw the complexity for what it really was: an opportunity to modernize and rethink how our global teams connect, create and deliver.

What if we could enable real-time, secure collaboration across every region without adding operational friction? What if our people could move faster, stay compliant by default and use AI not as a future vision but as a daily advantage? For us, this wasn’t just about keeping pace — it was about building a foundation that would power the future of client service, data intelligence and human-led innovation.

But this wasn’t just another migration. It was one of our biggest tech shifts yet — moving over 15 petabytes of data and 500,000+ mailboxes across 149 countries. With every territory bringing different business needs and risks and regulatory hurdles, we knew a one-size-fits-all approach wouldn’t work. This required precision, customization and flexibility — at global scale.

SOLUTION

Real change happens with people.

The biggest challenge in a migration isn’t always tech — it can be people. We started with people-first design by listening through employee surveys and creating a coalition of changemakers across our network. We rolled out continuously updated training and metrics. Our message was clear: We’re not doing this to you. We’re doing this with you.

Each member firm told us what they needed from governance frameworks to AI opportunity mapping. Off-the-shelf didn’t work at global scale — so we didn’t force it. In the US, we launched a pilot with 1,800+ users and, based on their feedback, built specialized apps to cut friction and fast-track user readiness. In China, India, Germany and other territories, we fine-tuned for compliance complexity, customizing everything from privileged identity management to future-proofed governance policies. We built custom solutions, fast-tracking what needed speed and co-designing what needed precision. From new compliance playbooks to tool-sharing coalitions, we turned complexity into clarity. All progress, no pause.

To cut costs and keep things running, we blended Microsoft and third-party tools into one toolkit. Thanks to our alliance, PwC and Microsoft engineers built enhancements — from smarter firewalls and VPNs to real-time notifications — all tailored to how we work across the globe. That meant resolving cross-platform coexistence issues head-on by fixing calendar sync bugs, enhancing VPN performance and deploying custom Microsoft updates like preserving declined meetings and improving co-authoring in PowerPoint. We also began laying the groundwork for Microsoft Copilot, introducing the AI assistant as part of a broader effort to reimagine how our people create, collaborate and deliver.

Different countries, different needs. Whether for compliance or client service, employee experience or new business opportunities, we delivered what our 149 member firms requested. We built real-time integrations across Microsoft Outlook, Teams and Power Platform and shifted to the Monthly Enterprise Channel (MEC) for faster, safer updates — giving our teams the latest features without downtime.

Countries like Germany, France, Luxembourg and Switzerland have particularly specific data sovereignty requirements, so we built in extra controls to facilitate segmentation of duties and privileged identity management. PwC Brazil and PwC India were especially concerned about the potential for new privacy laws, so we built tools to help future-proof their compliance. PwC France and our PwC US Advisory team wanted extra emphasis on speed, so we completed their migration in under two months and six weeks, respectively. Some territory firms had users already comfortable with Microsoft, others needed more extensive change management, so we had all new Microsoft capabilities fully up and running, with detailed training and guardrails provided, before we started to turn the old ones off.

RESULTS

Satisfaction, savings and accelerated AI

370,000 employees. One industry-leading platform. Our migration to the Microsoft 365 platform has helped revolutionize how we work, with Microsoft Copilot unlocking new horizons of intelligence, speed and innovation across our lines of service. With built-in multi-geo capabilities that allow our team to control where data is stored on a per user basis, we’ve made privacy and compliance easier, no matter where our teams sit. Microsoft Power Platform and Teams Voice simplify workflows so collaboration can flow effortlessly between our people and clients. It’s easier than ever to co-create, share and deliver in real time — giving clients faster access to insights, updates and outcomes.

Security got a serious upgrade too, with enhanced role-based access, end-to-end encryption and features like Microsoft Customer Lockbox and PwC’s Secure Fabric. Centralized data management with Microsoft Purview and Power BI have elevated governance — and unleashed more value from our data for AI and analytics. With enhanced architecture and OpenAI integration, we’re scaling AI like never before. And we’re not just working smarter — we’re saving smarter, too: $4 million annually from SharePoint migration in the US alone.

And we kept the lights on throughout. In some territories, we migrated up to 22,000 users per wave — all while layering on change journeys, localized governance and deep Microsoft co-engineering. No one-size-fits-all. All impact, no pause. This wasn’t just a migration. It was a leap into the future of connected work.

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Stephanie Mosticchio

Principal, US & Global Microsoft Alliance Leader, PwC US

Suzanne George

Cloud & Digital, Product Innovation Principal, PwC US

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