Office 365 vs Microsoft 365 — Behind the Rename, and a Practical Migration Strategy
Licensing The most frequent client question we hear: “Office 365, Microsoft 365 — same thing, right?” The answer is not short. On 21 April 2020 Microsoft did more than rename packages. This article explains the real differences between the two product families, which SKUs still ship under the “Office 365” brand, and what to weigh when choosing — grounded in Microsoft’s official sources.
When and why was the rename done?
Microsoft’s official announcement on 30 March 2020 repositioned the SMB Office 365 packages under the Microsoft 365 brand effective 21 April 2020.
Old → new naming:
- Office 365 Business Essentials → Microsoft 365 Business Basic
- Office 365 Business Premium → Microsoft 365 Business Standard
- Microsoft 365 Business → Microsoft 365 Business Premium
- Office 365 Business → Microsoft 365 Apps for Business
- Office 365 ProPlus → Microsoft 365 Apps for Enterprise
This applied only to SMB plans. Enterprise Office 365 E1, E3, E5 and F3 are still sold under the Office 365 brand today. Both brands coexist in Microsoft’s catalogue.
Just a name change, or new substance?
In the Business family the rename came with substance: Business Premium added Microsoft Intune + Microsoft Entra ID Plan 1 + Azure Information Protection P1 + Defender for Business — capabilities that were not in the old “Microsoft 365 Business” SKU.
For the Apps SKUs (Apps for Business / Apps for Enterprise) it was largely a rename — the underlying entitlements stayed the same.
For the Enterprise plans (E1/E3/E5) Microsoft introduced the parallel Microsoft 365 E3 / E5 SKUs alongside the existing Office 365 E3/E5. They’re different products, not the same thing under a new label.
What’s the actual difference between Office 365 E3/E5 and Microsoft 365 E3/E5?
| Component | Office 365 E3 | Microsoft 365 E3 | Office 365 E5 | Microsoft 365 E5 |
|---|---|---|---|---|
| Office apps + Exchange + SharePoint + Teams + OneDrive | ✓ | ✓ | ✓ | ✓ |
| Windows 11 Enterprise | ✗ | ✓ | ✗ | ✓ |
| Microsoft Intune | ✗ | ✓ | ✗ | ✓ |
| Microsoft Entra ID Plan 1 | ✗ | ✓ | ✗ | ✓ |
| Defender for Office 365 P1 | ✗ | ✗ (add-on) | ✓ | ✓ |
| Defender for Endpoint | ✗ | Plan 1 | ✗ | Plan 2 |
| Defender for Identity | ✗ | ✗ | ✗ | ✓ |
| Defender for Cloud Apps | ✗ | ✗ | ✗ | ✓ |
| Microsoft Purview Suite | ✗ | P1 | ✗ | Suite |
| Teams Phone | ✗ | ✗ | ✓ | ✓ |
| Power BI Pro | ✗ | ✗ | ✓ | ✓ |
| Entra ID Plan 2 | ✗ | ✗ | ✗ | ✓ |
In short:
- Office 365 E3/E5 = the Office productivity stack + Office-side security (E5 only).
- Microsoft 365 E3/E5 = Office 365 E3/E5 + Windows + EMS (Intune, Entra, Defender for Endpoint, Information Protection).
If you only need productivity + don’t manage the Windows estate from M365, Office 365 E3 can be enough. If you want unified endpoint + identity + security, Microsoft 365 E3/E5 is the right tier.
Which SKUs still ship as “Office 365”?
The plans still sold under the Office 365 brand:
- Office 365 E1 (web Office + Exchange + Teams + SharePoint, no desktop Office)
- Office 365 E3
- Office 365 E5
- Office 365 F3 (frontline workers)
- Exchange Online Plan 1 / 2 (mail-only)
If you don’t need Windows Enterprise + Intune + Entra in a single licence, the Office 365 family stays cost-effective.
A decision guide
| Profile | Recommended |
|---|---|
| SMB (up to 300 users), 2026 baseline | Microsoft 365 Business Premium |
| Mid-market, needs Windows + EMS centralised | Microsoft 365 E3 |
| Mid-market, heavy compliance / threat profile | Microsoft 365 E5 |
| Productivity-only, manages Windows separately | Office 365 E3 |
| Productivity-only with Teams Phone + Power BI | Office 365 E5 |
| Field staff / frontline | Microsoft 365 F1/F3 or Office 365 F3 |
Frequent confusions
Are M365 Apps for Business and M365 Business Standard the same? No. Apps for Business is just the Office desktop apps; no Exchange, SharePoint, Teams or OneDrive for Business. Business Standard adds the full collaboration stack.
Can I mix Office 365 and Microsoft 365 in the same tenant? Yes. Microsoft allows mixed SKUs in a tenant. The mix is often the most cost-effective answer.
Is migrating from Office 365 E3 to Microsoft 365 E3 invasive? No. The SKU change is a one-click upgrade in Admin Center; mailboxes, files and identities are untouched. The new capabilities (Intune, Entra P1, Defender for Endpoint) need to be configured to deliver value.
Bottom line
“Office 365” and “Microsoft 365” are not the same thing. The right pick depends on whether you want a productivity bundle (Office 365) or a productivity + endpoint + identity + security bundle (Microsoft 365). For a TCO comparison across your existing licence inventory and the right migration path, contact us for a free assessment.
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