Comparison

UnionStack vs Microsoft 365

The same enterprise productivity you rely on — with genuine European data sovereignty that Microsoft cannot provide.

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Productivity & Collaboration

Feature Microsoft 365 UnionStack
Email & Calendar
Outlook / Exchange Online
UnionStack Mail
Document Editing
Word / Excel / PowerPoint Online
UnionStack Docs
Video Conferencing
Microsoft Teams
UnionStack Meet
Team Messaging
Microsoft Teams
UnionStack Chat
File Storage
OneDrive / SharePoint
UnionStack Drive
Project Management
Planner / Project
UnionStack Projects

Security & Compliance

Feature Microsoft 365 UnionStack
Advanced Threat Protection
Microsoft Defender
UnionStack Shield
Data Loss Prevention
Microsoft Purview
UnionStack DLP
MFA / SSO
Entra ID
UnionStack Identity
Endpoint Management
Intune
UnionStack Endpoint
Customer-Managed Encryption Keys
Limited (extra cost)
Included
Zero-Knowledge Encryption
No
Available

Data Sovereignty

Feature Microsoft 365 UnionStack
Data stored exclusively in EU
Available (EU Data Boundary)
Guaranteed
No CLOUD Act exposure
No — Microsoft is US-headquartered
Yes — German GmbH
No FISA 702 obligations
No — Subject to FISA
Yes — EU law only
EU-only staff access
No — Global operations team
Yes — All staff EU-based
No US parent company
No — Microsoft Corp (US)
Yes — Independent GmbH
Sovereignty audit reports
Not available
Quarterly reports
GDPR-native architecture
Retrofit compliance
Built from ground up

Key Differentiators

True Legal Isolation

As a German GmbH with no US parent entity, UnionStack has no legal obligation to comply with US data access demands. Microsoft, as a US corporation, is legally compelled to comply with CLOUD Act orders — even for data stored in the EU.

Architecture, Not Just Policy

Microsoft's EU Data Boundary is a policy commitment. UnionStack's sovereignty is an architectural guarantee. Our systems are designed so that non-EU access is technically impossible, not just contractually prohibited.

Transparent Operations

We publish quarterly sovereignty audit reports, maintain a complete sub-processor list, and provide customer-managed encryption keys as standard. Microsoft's transparency around government data requests is limited.

Simpler Migration Than You Think

Our automated migration tools transfer email, files, calendars, and contacts from Microsoft 365 with zero downtime. Most enterprises complete the transition in 8-10 weeks with dedicated migration support.

Ready to Make the Switch?

Our migration team has helped hundreds of enterprises transition from Microsoft 365. Most complete the move in 8-10 weeks with zero downtime.