Best Microsoft 365 Consulting Firms

Best Microsoft 365 Consulting Firms (2026)

Microsoft 365 consulting in 2026 spans Microsoft Exchange Online, SharePoint Online, Microsoft Teams, Microsoft Viva, Microsoft Defender XDR, Microsoft Purview, Microsoft Entra, Microsoft 365 Copilot, and Microsoft Power Platform. This is the working enterprise buyer's guide for evaluating Microsoft 365 consulting firms — what to look for, what to avoid, and how to vet senior architects.

EPC Group has delivered Microsoft 365 consulting since 1997 — every major Microsoft enterprise productivity platform from Microsoft Exchange 5.5 through Microsoft 365 with Copilot.

TL;DR — What Makes Best-in-Class Microsoft 365 Consulting

Criterion	Why It Matters
Senior architect lead (10+ years)	Long arc of architectural context
All 6 Microsoft Solutions Partner designations	Cross-pillar integration depth
Microsoft Press authorship	Demonstrated technical leadership
Fixed-fee engagement model	Predictable cost, scope discipline
Industry-specific compliance experience	HIPAA / FINRA / FedRAMP / CMMC depth
Microsoft Purview governance depth	Compliance plane built-in
Microsoft 365 Copilot integration	Modern stack ready
vCAIO service offering	Strategic AI leadership

What Microsoft 365 Consulting Should Cover

Identity (Microsoft Entra ID)

• Microsoft Entra ID hybrid identity (Microsoft Entra Connect, Microsoft Entra Cloud Sync)
• Microsoft Entra ID Protection (risk-based blocking)
• Microsoft Entra Privileged Identity Management
• Microsoft Entra Conditional Access policies
• Microsoft Entra Identity Governance (access reviews, entitlement management)
• Microsoft Entra Verified ID

Productivity (Microsoft 365 Apps)

• Microsoft Exchange Online (mail, calendar, contacts)
• SharePoint Online (modern intranet, document management)
• Microsoft Teams (collaboration, voice, meetings)
• Microsoft OneDrive for Business (personal storage)
• Microsoft Viva (8-module employee experience)
• Microsoft Loop (collaborative components)
• Microsoft Stream (video)

Security (Microsoft Defender + Microsoft Purview)

• Microsoft Defender XDR (Endpoint, Office 365, Identity, Cloud Apps)
• Microsoft Sentinel (SIEM/SOAR)
• Microsoft Purview (sensitivity labels, DLP, retention, eDiscovery, Insider Risk, AI Hub)
• Microsoft Compliance Manager
• Microsoft Defender for Cloud Apps (BYOAI / Shadow AI governance)

AI (Microsoft Copilot Family)

• Microsoft 365 Copilot (productivity)
• Microsoft Copilot Studio (custom agents)
• Microsoft Power BI Copilot (analytics)
• Microsoft Copilot for Sales / Service / Security
• GitHub Copilot Business
• Microsoft Purview AI Hub for governance

Business Apps (Microsoft Power Platform)

• Microsoft Power Apps (custom business applications)
• Microsoft Power Automate (workflow automation)
• Microsoft Power Pages (customer-facing portals)
• Microsoft Dataverse (common data layer)
• Microsoft Power Platform Center of Excellence

What to Look For in a Microsoft 365 Consulting Firm

1. Senior Architect Depth

Critical question: Who is the named senior Microsoft 365 architect on the engagement?

Red flags:

• Engagement primarily staffed with junior consultants
• Senior architect is "available for escalation" but not actively engaged
• No specialization in 1-2 Microsoft 365 pillars (Identity, Security, AI)
• Senior architect joined firm <2 years ago

EPC Group standard: 10+ year senior architect leads engagement, with experience across multiple Microsoft 365 versions (Exchange 5.5 through Microsoft 365 Copilot).

2. Microsoft Solutions Partner Status

Verify the firm holds all 6 Microsoft Solutions Partner designations:

• Modern Work (Microsoft 365)
• Security (Microsoft Defender, Sentinel, Purview, Entra)
• Data & AI (Microsoft Fabric, Power BI, Microsoft Copilot)
• Business Applications (Microsoft Dynamics 365, Microsoft Power Platform)
• Infrastructure (Microsoft Azure)
• Digital & App Innovation (Custom Microsoft Azure applications)

EPC Group holds all 6 designations.

3. Microsoft Press Authorship

Errin O'Connor (EPC Group CEO) is a 4-time Microsoft Press author covering:

• Microsoft Power BI
• Microsoft SharePoint
• Microsoft Azure
• Microsoft enterprise architecture and migrations

4. Fixed-Fee vs Time-and-Materials

Fixed-fee engagements align consultant and customer interests on rapid, high-quality delivery. EPC Group standard: fixed-fee for all engagements.

5. Industry-Specific Compliance

For regulated industries, the firm must have demonstrated experience:

• Healthcare — HIPAA migrations, BAA, PHI sensitivity labeling
• Financial Services — FINRA Rule 3110, SEC Rule 17a-4, Information Barriers
• Government — Microsoft 365 GCC / GCC High, FedRAMP, CMMC
• Pharma — GxP, 21 CFR Part 11, FDA QSR

6. Microsoft Purview Governance Depth

Best-in-class Microsoft 365 firms scope:

• Microsoft Purview sensitivity label taxonomy
• Microsoft Purview DLP policies
• Microsoft Purview Audit (Premium) retention
• Microsoft Purview AI Hub for Microsoft Copilot
• Microsoft Compliance Manager attestation

7. Microsoft 365 Copilot Integration

Modern Microsoft 365 engagements include Microsoft 365 Copilot governance setup, oversharing remediation, Microsoft Copilot Studio agent design, and Microsoft Purview AI Hub configuration.

Engagement Patterns

Pattern 1: Microsoft 365 Migration

Migration from on-premises (Exchange, SharePoint Server) or third-party (Google Workspace, Lotus Notes) to Microsoft 365. EPC Group fixed-fee:

• Mid-market (1,000-5,000 users): $300K-$700K
• Enterprise (5,000-15,000 users): $700K-$2M
• Fortune 500 (15,000+ users): $2M-$8M

Pattern 2: Microsoft 365 Modernization

Existing Microsoft 365 tenants modernizing classic SharePoint, deploying Microsoft Viva Connections, or rolling out Microsoft 365 Copilot. EPC Group fixed-fee: $400K-$3M.

Pattern 3: Microsoft 365 Tenant-to-Tenant Migration

M&A integration, divestiture, regulatory restructuring. EPC Group fixed-fee: $300K-$8M depending on scale and complexity.

Pattern 4: Microsoft 365 Managed Services

Ongoing operations for Microsoft 365 + Microsoft Defender + Microsoft Purview + Microsoft Sentinel. EPC Group: $5K-$60K/month.

Pattern 5: Microsoft 365 Copilot Implementation

Microsoft 365 Copilot deployment with governance. EPC Group fixed-fee: $200K-$3M.

EPC Group Microsoft 365 Practice Differentiators

• Microsoft 365 experience since 1997 (started with Exchange 5.5 era)
• All 6 Microsoft Solutions Partner designations
• Microsoft Press authorship (Errin O'Connor, 4 books)
• Senior-architect-led delivery (no junior-consultant-heavy staffing)
• Fixed-fee discipline
• Industry-specific compliance frameworks
• Microsoft Purview governance depth
• Microsoft 365 Copilot integrated
• vCAIO service offering for ongoing AI leadership

Frequently Asked Questions

How much does Microsoft 365 consulting cost?

EPC Group fixed-fee:

• Mid-market: $300K-$700K per engagement
• Enterprise: $700K-$2M
• Fortune 500: $2M-$8M+
• Plus optional managed services: $5K-$60K/month

How long does a Microsoft 365 engagement take?

Mid-market: 6-9 months. Enterprise: 9-18 months. Fortune 500: 18-30 months.

What about Microsoft 365 Copilot?

Modern Microsoft 365 engagements include Microsoft 365 Copilot governance setup. EPC Group's Copilot for Microsoft 365 Complete Deployment Guide covers the full deployment framework.

What about regulated industries?

Healthcare (HIPAA), financial services (FINRA, SEC), government (FedRAMP, CMMC), and pharma (GxP) are EPC Group's primary Microsoft 365 customers.

Who delivers EPC Group Microsoft 365 engagements?

Errin O'Connor (CEO, 4-time Microsoft Press author) leads the practice. Senior architects with combined Microsoft 365 experience since 1997.

Next Steps

Schedule a 30-minute Microsoft 365 discovery call at /schedule or call (888) 381-9725. Senior architects (not sales) take discovery calls.

Related reading: End-to-End Microsoft Cloud Solutions Enterprise Guide, Copilot for Microsoft 365 Complete Deployment Guide, Microsoft 365 Tenant-to-Tenant Migration Enterprise Guide, Microsoft Purview Data Governance Enterprise Guide, and Delivery Excellence Microsoft Consulting.