Microsoft 365 E3 vs E5 — what's worth the upgrade

The difference between Microsoft 365 E3 and E5 is dramatic — both in cost (E5 is roughly 60–70% more expensive) and capabilities. Knowing which features actually justify the step-up, and how to mix the tiers, lets you get E5 value without paying for everyone.

What E3 includes (the baseline)

Microsoft 365 E3 covers the productivity core plus a basic security and identity layer:

• Microsoft 365 Apps for Enterprise — installable Office apps.
• Exchange Online (Plan 2) — 100 GB mailboxes with archive.
• SharePoint, OneDrive, Teams.
• Microsoft Entra ID P1 — Conditional Access, password writeback, SaaS provisioning.
• Microsoft Intune — endpoint management.
• Azure Information Protection P1 — sensitivity labels.
• Microsoft Purview baseline — basic retention, basic eDiscovery.
• Microsoft Defender Antivirus built into Windows.

This is enough for most knowledge workers in most organisations.

What E5 adds

E5 adds substantial capabilities across four areas:

Security

• Defender for Office 365 Plan 2 — Safe Links, Safe Attachments, AIR, attack simulation, Threat Explorer.
• Defender for Endpoint Plan 2 — full EDR, advanced hunting, TVM, Live Response.
• Defender for Identity — AD / Entra ID attack detection (sensor-based).
• Defender for Cloud Apps — SaaS posture management, CASB.

Compliance

• Purview Premium — Insider Risk Management, Communication Compliance, Information Barriers, Records Management, Premium eDiscovery, Customer Lockbox, Customer Key.
• Audit (Premium) — 1-year audit retention vs 180 days.

Identity

• Microsoft Entra ID P2 — Privileged Identity Management (PIM), Identity Protection, Access Reviews.

Analytics and communications

• Power BI Pro — sharing rights for Power BI reports.
• Teams Phone Standard — full phone-system features (Calling Plan minutes separate).

When E5 is worth it for everyone

• Regulated industries — financial services, healthcare, defence — where the compliance and security tooling is essentially required.
• High-risk-profile organisations — frequent targets of attack, valuable IP, public-sector targets.
• Heavy Power BI users — many users authoring and consuming reports.
• Teams Phone deployment — Phone Standard is bundled, replacing separate Teams Phone licensing.

For these, E5 across the tenant is the right call.

When E5 is overkill for everyone

• Smaller organisations without sophisticated security needs.
• Light Power BI usage — Pro can be bought per-user as needed.
• No Teams Phone plans — Phone Standard's value isn't realised.

For these, E3 with selective add-ons is more cost-effective.

The step-up pattern

Many tenants run E3 as the base with E5 step-up SKUs for specific users:

• Security team and SOC — full E5 for the tooling.
• Executives — E5 for advanced threat protection and PIM.
• Compliance officers — E5 for Premium eDiscovery, Insider Risk.
• Finance / Legal — E5 for sensitive-content handling.
• Heavy report authors — E5 for Power BI Pro.
• High-risk roles — anyone with payment authority or sensitive data access.

Microsoft offers specific step-up SKUs:

• E5 Security — adds the Defender stack on top of E3.
• E5 Compliance — adds the Purview compliance stack.
• Entra ID P2 — adds PIM and Identity Protection.
• Defender for Office 365 P2 — adds advanced email protection.

Each step-up costs less than the difference between E3 and E5, so you can build E5 capability for specific roles cheaper than upgrading everyone.

Operational considerations

• Track per-user licensing with periodic audit. Step-up SKUs get accidentally assigned then forgotten.
• Communicate clearly what each tier gets — users with different licences experience Microsoft 365 differently.
• Renew strategically — negotiate at EA / MCA renewal with actual usage data.

For most enterprises, the right answer is mixed: E3 broadly, E5 (or step-ups) for the roles that genuinely benefit. The cost difference between "E5 for everyone" and "E5 where needed" is often tens or hundreds of thousands per year for a medium-to-large tenant — worth getting right.

If you're under (or near) 300 seats, there's a decision before this one: whether you should be on the enterprise tier at all. See Business Premium vs Microsoft 365 E3.