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.