Office 365 vs Microsoft 365 — E3 and E5 comparison (2026)

Microsoft offers four enterprise suites: Office 365 E3, Office 365 E5, Microsoft 365 E3 and Microsoft 365 E5. The difference is in which productivity, security, management and analytics features are included. This article compares all four based on Microsoft's licensing guidance and helps you pick the right plan.

Quick overview — what's in each?

> Prices are recommended retail per user per month with annual prepay (CSP NCE, EUR excluding VAT). Check current rates in our Microsoft 365 CSP pricelist. "EOP only" refers to Exchange Online Protection — the basic email security built into every Microsoft 365 mailbox, without Safe Links / Safe Attachments / Attack Simulator.

The two product families

Microsoft 365 and Office 365 aren't the same suite under different names — they have a fundamentally different scope.

Office 365 (E3/E5) contains the Office apps (including desktop), email, collaboration and — with E5 — telephony, analytics and advanced email security. What it does not include: Windows licensing, Intune device management and the Microsoft Entra ID Premium / Defender for Endpoint stack. Suitable for organizations that already have their own Windows licensing and MDM/EDR solution.

Microsoft 365 (E3/E5) bundles Office 365 + Enterprise Mobility + Security (EMS) + Windows Enterprise. One license covers productivity, security, identity, device management and the operating system. For most enterprise customers this is the default.

What's included in all four?

• Microsoft 365 Apps for enterprise: — Word, Excel, PowerPoint, Outlook, OneNote and Access as desktop apps for PC and Mac
• Office for the web and mobile apps: — the same apps in browser/iOS/Android
• Exchange Online Plan 2: — 100 GB mailbox, in-place archive, DLP basics
• SharePoint Online Plan 2: — unlimited sites, content management
• OneDrive for Business Plan 2: — at least 5 TB storage per user
• Microsoft Teams: — chat, meetings, collaboration
• Microsoft Loop, Planner, To Do, Forms, Stream, Sway, Clipchamp
• Exchange Online Protection (EOP): — baseline anti-spam, anti-malware and anti-phishing for email

What does E5 add over E3?

Whether on Office 365 or Microsoft 365, the E5 upgrade adds the same four pillars:

1. Telephony & meetings

• Teams Phone Standard: — full cloud PBX (no separate PBX license required)
• Audio Conferencing: — dial-in to Teams meetings via local phone numbers

Without E5, Teams Phone Standard standalone is roughly €7.40/user/month and Audio Conferencing roughly €3.70/user/month.

2. Analytics

• Power BI Pro: — publish and share reports with colleagues. Standalone roughly €11.30/user/month.

3. Advanced email & collaboration security

• Defender for Office 365 Plan 2: — Safe Links, Safe Attachments, Threat Explorer, Attack Simulator and Automated Investigation & Response. E3 plans only get the baseline EOP protection; Plan 2 normally requires a separate add-on at roughly €4.60/user/month.

4. Compliance & investigations

• Advanced eDiscovery & Audit: — for legal hold, audit trails and forensic investigations

In Microsoft 365 E5 you additionally get: Defender for Endpoint Plan 2 (instead of Plan 1), Defender for Identity, Defender for Cloud Apps, Microsoft Entra ID P2, Purview Information Protection P2, Insider Risk Management and Communication Compliance.

What does Microsoft 365 add over Office 365?

Stepping from Office 365 to Microsoft 365 (at the same E-tier) adds the Enterprise Mobility + Security (EMS) stack and Windows Enterprise:

• Windows 11 Enterprise E3 or E5: — Credential Guard, Application Guard, AppLocker, BitLocker management, Long-Term Servicing options
• Microsoft Intune Plan 1: — manage Windows, macOS, iOS and Android from one console
• Microsoft Entra ID Premium: — Conditional Access, MFA policies, self-service password reset (P1) and risk-based policies, identity protection (P2)
• Microsoft Defender for Endpoint: — endpoint detection & response (Plan 1 in M365 E3, Plan 2 in M365 E5)
• Purview Information Protection (AIP): — sensitivity labels and encryption (P1 in M365 E3, P2 in M365 E5)

For an organization already buying separate solutions for MDM, Conditional Access or EDR, Microsoft 365 is usually cheaper than the standalone equivalents.

Which suite fits whom?

Office 365 E3 — productivity suite without the need for device management or Microsoft-supplied Windows licensing. Often picked by organizations with an existing MDM/EDR platform.

Office 365 E5 — for organizations that want to extend the productivity suite with Teams Phone, Audio Conferencing and Power BI Pro, but don't yet want to move to Microsoft 365.

Microsoft 365 E3 — the default choice for most enterprises: everything included to fully manage a modern workplace from Microsoft, including Windows and Intune. Suitable from around 50 employees where Business Premium (300-user cap) no longer fits.

Microsoft 365 E5 — for organizations with elevated security, compliance or analytics requirements: financial services, healthcare, government, or companies handling sensitive data. Insider Risk Management, Defender for Identity and Power BI Pro are often the deciding factors.

How much is the upgrade?

A move from Microsoft 365 E3 to E5 pays back quickly if you already use, or are evaluating, two or three of: Teams Phone, Power BI Pro and the advanced Defender licenses standalone.

Get tailored advice

We're happy to model which combination delivers the best value — including CSP partner discount, annual commitment savings, and an optional mix with Frontline (F-) licenses for production workers. Email support@universal.cloud or check the current CSP pricelist.