Microsoft 365 Enterprise Features & Licensing Guide

When should a UK business move from Business to Enterprise plans?

Move up only when a specific capability forces it — not because "Enterprise" sounds safer. The Business plans cap at 300 users and lack the legal-hold, archiving, and identity-governance tooling that regulated firms need. Below that threshold, the right Business plan is usually better value.

The four triggers that genuinely justify Enterprise:

• More than 300 users — the hard cap on Microsoft 365 Business plans.
• Compliance obligations — litigation hold, advanced eDiscovery, or sector rules (legal, financial services, public sector).
• Unlimited Office installs across every device a user owns.
• Windows Enterprise and advanced identity — Privileged Identity Management, Autopilot at scale.

If none of those apply, Microsoft 365 Business Premium at £16.90/user/month (Microsoft UK pricing) covers most 10–300 staff organisations. Our Microsoft 365 security service is built around getting that decision right before you overspend.

What are the Microsoft 365 Enterprise plan options?

There are three Enterprise SKUs. One is apps-only, the other two — E3 and E5 — are the plans most UK firms actually evaluate. The jump from E3 to E5 is almost entirely about advanced security and compliance, not productivity apps.

Microsoft 365 Apps for Enterprise — around £22–25/user/month (UK list price, 2026)

This gives desktop and mobile Office applications with no email, Teams, or SharePoint. It suits organisations that already run another email platform but want licensed Office apps for staff. It is uncommon in the UK SME market and mainly relevant in mixed-vendor environments.

Microsoft 365 E3 — around £28–33/user/month (UK list price, 2026)

E3 combines Office apps, Exchange Online (100GB mailbox), Teams, SharePoint, Intune, Microsoft Entra ID Premium P1, Windows Enterprise, and baseline compliance tools including litigation hold and standard eDiscovery. It is the right baseline when you have compliance duties or have outgrown the Business plans.

Microsoft 365 E5 — around £45–50/user/month (UK list price, 2026)

E5 layers Microsoft's advanced security and compliance onto E3: Defender for Endpoint Plan 2, Defender for Identity, Entra ID Premium P2 (Privileged Identity Management), advanced eDiscovery, Teams Audio Conferencing, and Power BI Pro. For security-mature firms it consolidates tooling that would otherwise need several separate products.

Which Enterprise features actually matter?

The features that justify the price gap are compliance and identity, not the apps — every plan ships the same Office and Teams. Below are the ones UK buyers ask about most, and where each one starts.

Litigation hold and in-place archive

Litigation hold preserves all mailbox content, including deleted items, regardless of user action — nothing can be permanently removed once a hold is applied. In-place archive adds expandable storage for older mail so the primary mailbox stays manageable. Both start at E3 and are common in law firms, financial services, and the public sector. Microsoft documents the retention behaviour in Microsoft Purview eDiscovery and hold guidance.

eDiscovery and audit

eDiscovery lets compliance and legal teams search across Exchange, Teams, SharePoint, and OneDrive using keyword, date, and user filters, then export results for disclosure. E3 includes standard eDiscovery; E5 adds advanced eDiscovery with machine-learning classification, custodian management, and review workflows.

Microsoft Entra ID Premium P1 and P2

P1 (in E3) provides conditional access, self-service password reset with on-premises writeback, and group-based licence management. P2 (E5 only) adds Privileged Identity Management for just-in-time admin elevation, Identity Protection for risk-based access, and access reviews. Microsoft details these tiers in the Entra ID licensing reference. We configure these for clients through conditional access policies and Microsoft Entra ID identity management.

Windows Enterprise

E3 and E5 carry Windows 11 Enterprise rights, enabling Autopilot zero-touch deployment, AppLocker, Device Guard, and enterprise BitLocker management. For businesses rolling out devices at scale, Autopilot removes most of the manual provisioning effort.

Microsoft Intune

Both E3 and E5 include Intune for mobile device and application management across Windows, macOS, iOS, and Android. It enforces compliance policies — PIN, encryption, current OS — and blocks non-compliant devices from business data. We deploy this through our Microsoft Intune management service.

How does Microsoft 365 Enterprise licensing work?

You buy Enterprise through one of three commercial routes, and the route changes your flexibility and price predictability more than the plan choice does. Most mid-market UK firms use CSP; only large organisations need an Enterprise Agreement.

• Enterprise Agreement (EA) — for 500+ users. Three-year volume licensing with predictable pricing and mid-term additions, managed via Microsoft's Large Account Resellers.
• Cloud Solution Provider (CSP) — the common mid-market route. A Microsoft-authorised partner supplies licences plus support, typically month-to-month or annual, with flexibility to add or remove seats. AMVIA is a CSP partner and provides E3/E5 alongside managed IT support.
• Microsoft Customer Agreement (MCA) — Microsoft's direct purchasing route via the admin portal, with annual or monthly subscriptions and no minimum user count.

Business Premium or E3 — which is right?

For most UK SMEs under 300 users, Business Premium is the better-value choice; E3 wins only when a specific compliance or scale requirement applies. The two overlap heavily on security, which is why the decision should be driven by named requirements, not feature-count comparisons.

Choose E3 when you need: 300+ users, litigation hold, 100GB mailboxes with expandable archive, advanced eDiscovery, or Windows Enterprise features. Choose Business Premium (£16.90/user/month) when none of those apply — it includes Microsoft Defender for Business, which gives SMEs strong endpoint protection at a lower price point.