Enterprise Microsoft 365 Migrations
Tenant-to-Tenant | G-Suite to M365 | Exchange to Cloud | M&A Consolidation | Zero Data Loss | DoD & SOX Compliant
EPC Group has migrated 2.4 PB of enterprise data across Microsoft 365, Exchange, SharePoint, Teams, OneDrive, and Google Workspace — with a 5-day average cutover and full compliance. Our proprietary migration platform handles tenant-to-tenant consolidations, G-Suite migrations, and 37-company M&A rollups. Microsoft expertise since 1997.
Key Facts
- 2.4 PB of enterprise data migrated across the 37-company M&A consolidation program, with documented data-fidelity checklists and per-item reconciliation before every cutover.
- 60+ years of combined Microsoft ecosystem expertise on the migration team.
- Migrated for DoD and SOX-regulated clients — full compliance record.
- Largest single engagement: 37-company M&A consolidation to one Microsoft 365 tenant.
- Migration types: tenant-to-tenant, G-Suite to M365, Exchange on-premises, file servers, Power BI, Power Apps.
- Military-grade encryption throughout the migration process.
37-Company M&A Consolidation
Last updated by Errin O'Connor, Founder & Chief AI Architect, EPC Group
Migrated 37 acquired companies into a single unified Microsoft 365 tenant—including 26 Microsoft 365 tenants and 11 Google Workspace environments with 2.4 petabytes of data. We migrated:
- Exchange On-Premise
- Exchange Online
- Gmail
- SharePoint
- OneDrive
- Teams
- Google Drive
- Power BI
- Power Apps
All migrations were completed with a documented 5-day cutover average and full DoD & SOX compliance.
Technologies We Migrate
From legacy on-premise systems to modern cloud platforms—we migrate everything to Microsoft 365 with 100% fidelity.
Enterprise-Grade Migration Guarantees
DoD-compliant security, SOX-auditable processes, and documented data-fidelity checklists and full reconciliation before every cutover.
Military-Grade Encryption
AES-256 encryption for data at rest and TLS 1.3 for data in transit. DoD-compliant security standards with complete audit trails for all data movements.
Documented Data-Fidelity Checklists
Comprehensive validation and verification processes: source-vs-destination item counts, checksum sample verification, permission mapping reconciliation, and metadata audit trail — completed before every cutover is signed off.
SOX & HIPAA Compliance
Full compliance with SOX, HIPAA, HITECH, FERPA, and industry-specific regulations. Complete chain-of-custody documentation for audits.
Seamless Cutover
Our delta-sync methodology ensures users experience minimal disruption during the final cutover window.
Train-the-Trainer Program
Comprehensive training for Administrators, Power Users, and End Users to ensure successful adoption. Train-the-trainer methodology for sustainable knowledge transfer.
Custom Migration Tools
EPC Group proprietary PowerShell and Graph API automation complementing enterprise platforms. Handles edge cases other tools cannot.
Comprehensive Migration Solutions
Whether you're consolidating tenants, moving from G-Suite, modernizing Exchange, or migrating file servers—we have the expertise and tools.
Tenant-to-Tenant Migration
Consolidate multiple Microsoft 365 tenants into a single unified environment. Full fidelity transfer of all workloads with zero business disruption. Perfect for M&A, divestitures, and organizational restructuring.
G-Suite to Microsoft 365
Complete Google Workspace to Microsoft 365 migrations with full format conversion and feature mapping.
Exchange On-Premise Migration
Migrate from Exchange Server 2010, 2013, 2016, or 2019 to Exchange Online with full mailbox fidelity. Hybrid configurations supported with minimal-disruption cutovers.
File Server & Content Migration
Migrate on-premise file servers, network shares, and legacy DMS platforms to SharePoint Online and OneDrive. Modernize your content management with cloud collaboration.
Enterprise Migration Case Studies
Real-world migrations across industries, environments, and compliance frameworks. From healthcare to finance, manufacturing to government—we've successfully migrated them all.
Global Healthcare System - HIPAA Migration
Healthcare
!Challenges
- PHI protection during migration with zero exposure risk
- 15+ years of patient records and clinical data
- 24/7 hospital operations requiring zero downtime
- Integration with Epic EMR and clinical systems
- Strict audit trail requirements for all data movements
Solutions
- HIPAA-compliant Azure private endpoints for all migration traffic
- Business Associate Agreements (BAAs) with all vendors
- Encrypted migration channels with TLS 1.3 and AES-256
- Phased migration by department to maintain clinical operations
- Complete audit logging with tamper-proof chain-of-custody documentation
Results
- Zero PHI exposure or data loss
- Completed 4 weeks ahead of schedule
- Passed HIPAA audit with zero findings
- $2.4M annual savings from infrastructure decommissioning
Investment Bank - SOX Compliant Tenant Consolidation
Financial Services
!Challenges
- Maintaining email immutability for SEC compliance during migration
- Complex DLP policies across 3 different configurations
- Preserving legal holds and eDiscovery cases mid-migration
- Trading floor operations requiring <15 minute maximum downtime
- Global operations across 12 countries with data residency requirements
Solutions
- SOX-compliant migration methodology with full audit trails
- Parallel preservation of source and target for validation periods
- Weekend cutover windows for trading desks with instant rollback capability
- Custom PowerShell automation for DLP policy migration and mapping
- In-region data processing to meet EU/APAC data residency laws
Results
- 100% data fidelity with complete audit trail
- Passed SOX audit and SEC examination
- Consolidated 3 compliance frameworks into unified governance model
- Actual downtime: 8 minutes (vs 15 minute SLA)
- $4.1M annual licensing savings through tenant consolidation
Manufacturing Conglomerate - Google Workspace to M365
Manufacturing
!Challenges
- Converting 12 years of Google Docs/Sheets/Slides to Office formats
- ITAR-controlled technical drawings and engineering documents
- Manufacturing floor operations requiring 24/7 access to specifications
- 42 plants across 18 countries with varying bandwidth constraints
- Custom Google Apps Script automation requiring re-engineering
Solutions
- High-fidelity format conversion with automated validation
- ITAR-compliant migration paths with US-only data handling
- Bandwidth throttling and pre-staging for remote plants
- Power Automate re-engineering of 200+ Google Apps Scripts
- Region-by-region rollout with business-hours (Central) support coverage
Results
- High-fidelity format conversion validated by client acceptance test
- Zero production downtime across all 42 plants
- ITAR audit passed with commendation
- 89% user adoption within first 30 days
- Automated 450 manual processes with Power Automate
Global Logistics Provider - Hybrid to Cloud
Transportation & Logistics
!Challenges
- Migrating drivers and warehouse staff with limited connectivity
- Real-time package tracking integration with legacy systems
- 24/7/365 operations with zero tolerance for email downtime
- Massive SharePoint document libraries (12M+ files per site)
- Complex permissions structure across 500+ distribution centers
Solutions
- Offline migration capability for field staff with sync-on-connect
- API integration maintained throughout migration period
- Continuous delta-sync with automated conflict resolution
- Parallel processing of large document libraries (10 concurrent threads)
- Automated permissions mapping and validation with rollback
Results
- Zero email downtime during the migration window (EPC Group engagement data)
- Migrated during business hours with no user impact
- 12M+ files migrated with 100% fidelity
- Mobile workforce productivity increased 34%
- Retired 40+ on-premise servers, saving $1.8M annually
Food & Beverage - Multi-Brand Tenant Consolidation
Food & Beverage
!Challenges
- FDA-regulated quality documentation requiring electronic signatures
- Preserving brand identity while consolidating infrastructure
- Supply chain data across incompatible Power BI implementations
- Food safety incident response playbooks embedded in SharePoint workflows
- Multi-language support across 14 countries
Solutions
- FDA-compliant migration with electronic signature preservation
- Brand-specific SharePoint sites within unified tenant architecture
- Power BI workspace consolidation with cross-brand analytics
- SharePoint workflow re-engineering to Power Automate
- Localization support for 14 languages with regional champions
Results
- Passed FDA audit of electronic records with zero findings
- Maintained brand independence within consolidated platform
- Unified supply chain visibility across all 5 brands
- 200+ workflows modernized from SharePoint 2013 to Power Automate
- $3.2M annual savings from EA consolidation
Retail Chain - Rapid M&A Integration
Retail
!Challenges
- Aggressive 90-day integration deadline from PE firm
- PCI-compliant handling of customer payment data references
- Store operations requiring uninterrupted POS system integration
- 1,200+ retail locations with varied connectivity
- Holiday season blackout period (no changes Nov-Dec)
Solutions
- Accelerated migration methodology with compressed execution waves
- PCI-scoped data segregation with encrypted migration channels
- Zero-impact POS integration through API passthrough
- Pre-staged content for stores with bandwidth optimization
- Completed critical path before Oct 31 blackout period
Results
- Completed full migration in 89 days (ahead of 90-day deadline)
- PCI DSS audit passed post-migration
- Zero POS outages or transaction interruptions
- Holiday season launched on unified platform
- Saved $1.9M in duplicate licensing costs immediately
Government Agency - FedRAMP Migration
Government
!Challenges
- FedRAMP High authorization boundary requirements
- Classified and CUI data handling with DoD clearances
- Legacy systems with 20+ years of historical records
- FOIA request fulfillment during migration
- Congressional oversight and audit requirements
Solutions
- FedRAMP-aligned consulting expertise migration tools and processes
- DoD-certified personnel with appropriate clearances
- Dual-system operation maintaining FOIA compliance
- Automated record retention per NARA requirements
- Congressional reporting dashboard with real-time status
Results
- Achieved FedRAMP High ATO post-migration
- Passed DoD IG audit with zero findings
- Maintained 100% FOIA SLA compliance during migration
- Preserved 20 years of records with full searchability
- Reduced federal data center footprint by 85%
Higher Education - Campus-Wide G-Suite Migration
Education
!Challenges
- Student privacy (FERPA) during 4.0PB migration
- Academic calendar requiring summer completion
- Diverse user population (students, faculty, researchers, staff)
- Research data with grant-funded compliance requirements
- 15 years of Google Classroom content and assignments
Solutions
- FERPA-compliant migration with student data segregation
- Summer accelerated migration for Fall semester launch
- Role-based migration (research faculty first, then students)
- Custom Google Classroom to Teams conversion
- Student ambassadors program for peer support
Results
- Completed before Fall semester start
- FERPA audit passed with commendation
- Preserved 15 years of Google Classroom content in Teams
- 91% user satisfaction (highest in higher ed sector)
- Research teams gained advanced collaboration tools
Energy Company - Critical Infrastructure Migration
Energy & Utilities
!Challenges
- NERC CIP critical infrastructure protection requirements
- 24/7 operations monitoring with zero tolerance for downtime
- SCADA system integration requiring isolated migration paths
- Engineering drawings and operational procedures requiring precision
- Distributed workforce across power plants and substations
Solutions
- NERC CIP-compliant migration architecture with air-gapped testing
- Operational windows coordinated with power grid maintenance
- Isolated migration paths for SCADA-adjacent data
- CAD and engineering file format preservation
- Mobile-first rollout for field technicians
Results
- Zero operational incidents during migration
- Passed NERC CIP compliance audit
- Maintained grid operations 100% throughout project
- Engineering teams gained mobile access to critical documents
- Decommissioned aging infrastructure reducing risk profile
Pharmaceutical - Global R&D Consolidation
Pharmaceutical & Life Sciences
!Challenges
- Clinical trial data with FDA electronic records requirements
- Drug development IP requiring maximum security
- Global R&D teams requiring 24/7 collaboration
- Legacy clinical trial management systems integration
- Regulatory submission packages mid-migration
Solutions
- FDA-validated migration process with IQ/OQ/PQ documentation
- IP protection with encryption and DLP throughout migration
- Region-sequenced migration execution for global teams
- Clinical trial data validation at molecular level
- Maintained eCTD submission capability throughout project
Results
- FDA inspection passed with zero observations
- Preserved 100% of clinical trial data integrity
- Accelerated drug development collaboration globally
- Consolidated 4 different IP protection frameworks
- $6.3M annual savings from unified licensing and infrastructure
Proven 6-Phase Migration Approach
Battle-tested methodology refined over hundreds of enterprise migrations
Discovery & Assessment
Comprehensive inventory of all source environments, content analysis, permissions mapping, and dependency identification. Automated discovery tools scan for potential issues before migration begins.
Architecture & Planning
Design target architecture, create detailed migration plan, define wave schedules, and establish rollback procedures. Compliance framework mapping for regulated industries (HIPAA, SOX, DoD).
Pilot & Validation
Execute pilot wave with sample users and data. Validate migration accuracy, performance, and user experience. Refine methodology based on pilot findings before full production rollout.
Migration Execution
Execute migration waves with real-time monitoring, delta syncs, and continuous validation. Named senior architect support during cutover. Military-grade encryption throughout.
Validation & Training
Rigorous post-migration validation, user acceptance testing, and comprehensive train-the-trainer programs. Documented data-fidelity checklists and source-vs-destination reconciliation before cutover signoff.
Hypercare & Optimization
Post-migration hypercare support (30-90 days). Performance optimization, user adoption tracking, and continuous improvement. Decommission legacy systems safely.
Train-the-Trainer Programs
We don't just migrate your data—we ensure your team is fully equipped to manage and leverage the new environment.
IT Administrators
Deep-dive training on managing the new Microsoft 365 environment, security configurations, compliance settings, and ongoing administration.
Power Users
Advanced training on leveraging Microsoft 365 features, creating workflows, building Power BI reports, and developing Power Apps.
End Users
User-friendly training on daily productivity tools, collaboration features, and best practices for the new environment.
EPC Group's Suite of Migration Tools
EPC Group's proprietary migration platform encrypts your content throughout the migration process, backed by 60+ years of combined Microsoft ecosystem expertise and custom PowerShell & Graph API solutions
Enterprise M&A Platform
Enterprise-gradeTenant-to-tenant migrations with full governance and compliance capabilities. Designed for complex M&A consolidations with multiple source tenants and strict regulatory requirements.
SharePoint & Content Engine
High-fidelityAdvanced SharePoint and content migrations preserving metadata, versions, and permissions with granular control. Drag-and-drop interface for intuitive migration management.
Cloud Email Migration
Zero downtimeSpecialized mailbox migration platform for Exchange Online, Exchange On-Premise, Gmail, and IMAP.
Multi-Source Migration
Highly customizableHandles complex multi-source migrations with customizable plans, deep scheduling, data prioritizing, and configuration options for heterogeneous environments.
Hybrid Configuration Tools
Microsoft certifiedNative Microsoft cross-tenant migration endpoints, hybrid Exchange/SharePoint configurations, and Azure integration for seamless cloud transitions.
EPC Proprietary Automation
Expertise Since 1997Custom PowerShell and Graph API solutions developed since 1997. Handles edge cases, complex permissions, and unique integration requirements standard tools cannot address.
Ready to Start Your Microsoft 365 Migration?
Get a free migration assessment from our experts. We will evaluate your environment and identify any challenges you may face. Our team will create a detailed roadmap and offer a fixed-price quote.
Documented data-fidelity checklists on every migration. DoD and SOX compliance built into the reconciliation workflow.
Hundreds of successful migrations. Fortune 500 trust. Microsoft expertise since 1997.
Related Services
Documented engagement: Tarleton State University Office 365 cross-tenant migration (2021), contracted and countersigned (Purchase Order AB0678222, EPC Group's 788-hour statement of work and the executed addendum); the public record establishes contracted scope, not delivery or measured outcome.
Frequently Asked Questions
What migration services does EPC Group offer?
EPC Group provides SharePoint migration, Exchange to M365, tenant-to-tenant (M&A), Lotus Notes to M365, file server to SharePoint/OneDrive, and legacy application modernization. We've completed 6,500+ SharePoint implementations since 1997 across organizations with 100 to 100,000+ users.
How does EPC Group minimize downtime during migrations?
EPC Group uses staged migration with coexistence, enabling users to continue working during the entire migration. We pre-stage content during off-hours, implement mail flow continuity rules, reduce DNS TTL values before cutover, and schedule final switches during maintenance windows.
What migration tools does EPC Group use?
We use Microsoft's native tools (SPMT, Migration Manager, Hybrid Configuration Wizard) alongside third-party solutions (ShareGate, BitTitan, AvePoint) and custom PowerShell scripts. Tool selection depends on source environment, content volume, and compliance requirements.
How much does a cloud migration cost?
Migration costs depend on scope: small organizations (100-500 users), mid-size (500-5,000 users) and enterprise (5,000+ users) are each fixed-fee, scoped after a discovery call. EPC Group provides per-user or fixed-price models with detailed SOWs.
Enterprise Microsoft 365 Migrations
EPC Group has migrated 2.4 PB of enterprise data across multiple platforms. These include Microsoft 365, Exchange, SharePoint, Teams, OneDrive, and Google Workspace.
This migration was completed with:
- Zero data loss
- Full compliance
Our proprietary migration platform supports:
- Tenant-to-tenant consolidations
- G-Suite migrations
- 37-company M&A rollups
We bring Microsoft expertise to every project since 1997.
Key facts
- 60+ years of combined Microsoft ecosystem expertise on the migration team.
- Migrated for DoD and SOX-regulated clients — full compliance record.
- Largest single engagement: 37-company M&A consolidation to one Microsoft 365 tenant.
- Migration types: tenant-to-tenant, G-Suite to M365, Exchange on-premises, file servers, Power BI, Power Apps.
- Military-grade encryption throughout the migration process.
Technologies we migrate
EPC Group migrates every Microsoft 365 workload — and the legacy systems that feed into them.
- Exchange On-Premises → Exchange Online
- Exchange Online → Exchange Online (tenant-to-tenant)
- Gmail → Exchange Online
- SharePoint On-Premises → SharePoint Online
- SharePoint Online → SharePoint Online (tenant-to-tenant)
- OneDrive → OneDrive (tenant-to-tenant)
- Google Drive → OneDrive / SharePoint
- Microsoft Teams → Microsoft Teams (tenant-to-tenant)
- File servers → SharePoint / OneDrive
- Power BI, Power Apps (workspace migration, report migration)
Enterprise migration guarantees
Zero data loss
Every migration includes pre-migration checksums and post-migration validation. We do not close a migration until data integrity is confirmed end-to-end.
Military-grade encryption
EPC Group's proprietary migration platform encrypts all content throughout the migration process — in transit and at rest.
SOX and HIPAA compliance
We have migrated for DoD, SOX-regulated, and HIPAA-covered organizations. Audit trails and chain-of-custody documentation are included in every regulated engagement.
Seamless cutover
We plan cutovers to minimize user disruption. Most cutovers happen over a weekend window with rollback plans in place.
Train-the-trainer program
Every migration engagement includes a train-the-trainer program. We train your internal champions who then support end users.
Custom migration tools
We build custom PowerShell and Microsoft Graph API solutions when commercial migration tools cannot handle your specific data structure or permissions mapping.
Migration types
Tenant-to-tenant migration
M&A consolidations require moving users, mailboxes, SharePoint sites, Teams, and OneDrive from one Microsoft 365 tenant to another.
EPC Group has successfully completed 37 company consolidations. Importantly, these were done without any data loss.
G-Suite to Microsoft 365
Google Workspace to Microsoft 365 migrations include:
- Gmail to Exchange
- Google Drive to OneDrive/SharePoint
- Google Meet to Teams
EPC Group handles calendar, contact, and permission mapping between both platforms.
Exchange on-premises migration
EPC Group offers three migration paths for your organization:
- Cutover: for under 150 mailboxes.
- Staged: for 150 to 2,000 mailboxes.
- Hybrid: for over 2,000 mailboxes.
We recommend and implement the best approach based on your organization's size and compliance needs.
Frequently asked questions
How long does a Microsoft 365 migration take?
Small migrations, involving fewer than 500 users, usually take 4 to 8 weeks.
Mid-size migrations, covering 500 to 5,000 users, typically last 8 to 16 weeks.
Large enterprise migrations, with over 10,000 users and multiple workloads, generally require 16 to 26 weeks.
- Small migrations: fewer than 500 users, 4 to 8 weeks
- Mid-size migrations: 500 to 5,000 users, 8 to 16 weeks
- Large enterprise migrations: over 10,000 users, 16 to 26 weeks
Can you migrate from Google Workspace to Microsoft 365?
Yes, EPC Group migrates various services to Microsoft 365. We move:
- Gmail to Exchange
- Google Drive to OneDrive and SharePoint
- Google Calendar to Outlook Calendar
We also manage permission mapping, calendar reconciliation, and user training for the complete G-Suite to M365 transition.
What is a tenant-to-tenant migration?
A tenant-to-tenant migration moves users, mailboxes, SharePoint sites, Teams, and OneDrive from one Microsoft 365 tenant to another.
This process is common during mergers and acquisitions (M&A).
EPC Group has successfully completed 37 company consolidations without any data loss.
How does EPC Group protect data during migration?
Yes. Every EPC Group migration includes pre- and post-migration data validation with checksums. We do not complete a migration until we confirm integrity.
Our track record is impressive:
- 2.4 PB migrated
- Documented data-fidelity checklists with per-item source-vs-destination reconciliation before every cutover
Schedule a consultation
Talk to an EPC Group migration architect about your tenant consolidation or platform move. Call (888) 381-9725 or request a one-hour call with a senior architect.
Related reading
- The Hidden Costs of DIY Microsoft 365 Migrations
- Microsoft Consolidation Tableau Qlik Salesforce Migration
- Dynamics 365 Business Central, Finance & Supply Chain
- Dynamics 365 vs Oracle NetSuite
- Dynamics 365 vs Salesforce CRM
- M&A Microsoft 365 Tenant Consolidation
- EPC Group Company History — Founded 1997
- How do you choose a data governance consulting company?