Microsoft 365 Business Premium or E3: which should we buy?

Key facts

• Business plans, including Business Premium, are capped at 300 users per plan.
• Business Premium includes Defender for Business and Defender for Office 365 Plan 1; E3 does not include either.
• Both include Entra ID P1, Intune and the desktop Microsoft 365 apps.
• E3 includes Windows Enterprise E3 and larger primary mailboxes.
• Enterprise suites for new subscriptions are generally sold without Teams, which is licensed separately.

The short comparison

Business Premium is Microsoft's security-focused suite for small and mid-size businesses. Microsoft 365 E3 is the core enterprise suite. They overlap a lot, but they are not a straight upgrade path: Business Premium includes some security features that E3 does not, while E3 includes enterprise features and has no seat cap.

Plan contents change over time, so confirm current service descriptions before purchase. The table reflects the general shape of each plan in late 2026.

When Business Premium is the right choice

• You have fewer than 300 users and do not expect to pass that soon.
• You want endpoint detection and response and email phishing protection without buying add-ons.
• You need Conditional Access, Intune and Autopilot but not Windows Enterprise features.
• Your compliance needs are covered by retention policies, sensitivity labels and basic eDiscovery.
• You want one license that covers the security baseline most cyber insurers ask about.

When E3 is the right choice

If you move to E3, plan the security gap. E3 does not include Defender for Office 365, so add Plan 1 or Plan 2, or an E5 Security add-on, rather than relying on Exchange Online Protection alone.

• You have more than 300 users, or expect to pass that limit through growth or an acquisition.
• You need Windows Enterprise features or plan to use Windows Enterprise licensing benefits.
• Users need larger primary mailboxes.
• Legal or compliance teams need broader Purview retention and eDiscovery capabilities.
• You plan to step up to E5 or E5 Security and Compliance add-ons later.

Mixing plans in one tenant

You can mix Business and Enterprise licenses in the same tenant. A common pattern is Business Premium for most users, with E3 or E5 for a small group that needs enterprise features, or Frontline licenses such as F1 or F3 for staff who use shared devices or only need limited apps.

When you mix plans, check that your policies match the licenses. Conditional Access and Intune policies work across Business Premium and E3 because both include Entra ID P1 and Intune. Defender features differ, so a mixed tenant may have users on Defender for Business and others on Defender for Endpoint, which affects how you manage alerts.

If you are near the 300-seat cap, model the next two to three years. Moving later means a license transition, not a data migration, but it still takes planning around renewal dates and feature differences.

Pricing and renewal considerations

Microsoft sets list prices and changes them from time to time, and resellers and partners offer different terms. Compare plans on a total basis: the base suite plus any add-ons you would need to reach the same security posture. Business Premium often looks more expensive than Business Standard but replaces several add-ons. E3 often needs Defender for Office 365 and Teams added to match what users already have.

Check your term length and renewal date before switching. Annual-term subscriptions under Microsoft's New Commerce Experience generally cannot be reduced mid-term outside a short cancellation window, so time plan changes with your renewal.

How Accred Consulting approaches it

Accred Consulting reviews your user count, growth plans, security requirements, compliance needs and current add-ons during discovery, then recommends a license mix rather than a single plan for everyone. The recommendation covers which users need Business Premium, E3, E5 add-ons or Frontline plans, and how Conditional Access, Intune and Defender policies map to each. Accred then configures the controls those licenses include, so you use what you pay for. The work is scoped with a fixed price and delivered by US-based specialists with 11 years of hands-on Microsoft delivery experience on the practice team.

Track record: 475+ client projects, 2,000+ migration workstreams and 210,000+ users migrated by a US-based team. Company facts · Case studies

Related questions