Microsoft 365 E3 vs E5: which to choose for Modern Work

The question shows up in nearly every modern-work project: E3 or E5? The short answer is "it depends," but it depends on concrete factors you can map. This article separates what actually differs between the two Microsoft 365 plans and helps you avoid two classic mistakes — paying for E5 and using it like E3, or saving with E3 and re-buying, piece by piece, everything E5 would have delivered.

What both plans share

Both E3 and E5 include the Modern Work foundation:

• Office apps (Word, Excel, PowerPoint, Outlook) for desktop, web and mobile.
• Exchange Online, SharePoint Online, OneDrive and Teams.
• Entra ID P1, with Conditional Access and MFA.
• Device management with Intune.
• Basic retention and discovery.

In other words: for collaboration, email and pure productivity, E3 already delivers a complete platform. The difference lives in the advanced security, compliance and voice layers.

What only E5 delivers

E5 is essentially E3 plus three blocks of value:

1. Advanced security

• Microsoft Defender for Office 365 Plan 2 — protection against advanced phishing, malicious attachments and links, plus automated investigation.
• Defender for Endpoint Plan 2 — full EDR on devices.
• Entra ID P2 — risk-based Conditional Access, access reviews and Privileged Identity Management (PIM).

2. Compliance and governance

• Advanced Microsoft Purview: automatic sensitivity labeling, expanded data loss prevention (DLP), records management and insider risk.
• Premium eDiscovery for complex legal matters.

3. Voice and analytics

• Teams Phone with a calling plan (region-dependent).
• Power BI Pro included.
• Advanced meeting and productivity analytics.

How to decide in practice

The choice is rarely ideological; it is about use case. Use these triggers:

The "middle ground via add-ons" trap

Many companies start on E3 and keep buying add-ons: Defender here, Power BI there, Teams Phone later. When it all adds up, the per-user cost frequently exceeds E5 — without the integration and management simplicity of a single bundle. So run the full math before deciding.

On the other hand, giving E5 to 100% of the base when only 20% need EDR and advanced compliance is waste. The most efficient approach is usually mixed: E5 for people handling sensitive data, holding privileged access or using voice; E3 for the operational majority.

Licensing by persona

A typical segmentation:

1. Executives and privileged IT — E5, for identity security (PIM, risk-based access).
2. Legal, finance, HR — E5, for compliance and DLP.
3. General operations — E3, with targeted add-ons if needed.
4. Frontline workers — F plans, more economical, for people who mainly use Teams and mobile apps.

Key takeaways

• E3 and E5 share the entire collaboration foundation; the difference is security, compliance and voice.
• Add up the add-ons before choosing E3 — the total usually passes E5.
• Mixed licensing (E5 for a critical few, E3 for the majority) is almost always most efficient.
• Frontline workers can use much cheaper F plans.
• Decide by use case, not by fashion.

As a CSP partner, RHC models the license mix by user persona, aligning E3, E5, add-ons and F plans to each client's real risk and budget.