Microsoft 365 E3: Enterprise Plan Features & Pricing

What Is Microsoft 365 E3?

Microsoft 365 E3 is the entry-level enterprise plan in Microsoft's 365 portfolio, sitting above the Business tier (Basic, Standard, Premium) and below E5. It is designed for larger organisations — technically available from 1 user, but typically adopted by businesses with 300+ staff or those requiring capabilities that Business plans don't provide.

At £30.20/user/month, E3 is significantly more expensive than Business Premium (£17.60/user/month). The question of whether the uplift is justified comes down to specific compliance, identity and governance requirements.

What's Included in Microsoft 365 E3

Productivity Applications

• Installed Office apps — Word, Excel, PowerPoint, Outlook, OneNote, Access, Publisher — unlimited installs per user (Business plans limit to 5 devices per user)
• Office mobile apps — unlimited device installs
• Office web apps
• Microsoft Teams — full meeting and collaboration features
• Exchange Online Plan 2 — 100GB mailbox, in-place archiving, litigation hold
• OneDrive for Business — 1TB per user (with expansion to unlimited in large tenants)
• SharePoint Online Plan 2

Identity and Access Management

• Azure Active Directory Premium P1 — conditional access policies, risk-based sign-in, group-based access management, Azure AD Application Proxy
• Azure AD Premium P1 features include self-service password reset with on-premises writeback, hybrid Azure AD join, and enterprise state roaming

Compliance and Information Protection

• Microsoft Purview (formerly Microsoft Compliance Centre)
• Litigation hold and in-place archive — retain all mailbox content for legal purposes
• eDiscovery — search and export content across Exchange, Teams, SharePoint and OneDrive
• Audit logs — detailed audit trail for user and admin activity
• Microsoft Information Protection Plan 1 — sensitivity labels, basic DLP
• Communication compliance (basic)

Security

• Microsoft Defender for Office 365 Plan 1 — Safe Links, Safe Attachments, anti-phishing
• Windows 11 Enterprise E3 — enterprise device management features
• Microsoft Intune — device and application management

Key Differences Between E3 and Business Premium

Business Premium (£17.60/user/month) and E3 (£30.20/user/month) share many features. The main upgrades in E3 are:

• Unlimited Office installs vs 5 devices in Business plans — relevant in device-heavy environments (manufacturing, retail, healthcare)
• 100GB Exchange mailbox vs 50GB — and unlimited archiving
• Litigation hold — retaining deleted emails and content for legal proceedings
• Full eDiscovery — required for organisations subject to legal discovery obligations
• Advanced audit logs with longer retention periods
• Windows Enterprise licence — includes Windows Autopilot for zero-touch device deployment and Windows Enterprise security features

For organisations in financial services, legal, healthcare or public sector where data retention and eDiscovery are compliance requirements rather than nice-to-haves, E3 is frequently the appropriate baseline.

What E3 Does Not Include

E3 is a comprehensive plan but it doesn't include everything Microsoft offers. Notable omissions compared to E5:

• Teams Audio Conferencing — dial-in to meetings by phone (requires add-on)
• Teams Phone System — PSTN calling capability (requires add-on)
• Microsoft Defender for Endpoint P2 — advanced endpoint security
• Microsoft Purview advanced compliance — insider risk management, advanced eDiscovery, communication compliance
• Azure AD Premium P2 — Privileged Identity Management (PIM), Identity Protection
• Power BI Pro

When to Choose E3

E3 makes sense for organisations that:

• Have 300+ users (above the Business plan cap)
• Require litigation hold and eDiscovery for compliance or legal purposes
• Need unlimited Office installs across a large, device-heavy workforce
• Are pursuing ISO 27001, Cyber Essentials Plus or sector-specific compliance where audit trail requirements exceed what Business plans provide
• Use Windows devices and want to take advantage of Windows Enterprise features and Autopilot

For businesses under 300 users with standard Office and security needs, Business Premium typically provides better value at £17.60/user/month. AMVIA can help assess whether the E3 upgrade is justified for your specific requirements.