Microsoft 365 vs Office 365: Current Plan Differences in 2026

Office 365 and Microsoft 365 are no longer interchangeable names. In 2026, Office 365 generally means productivity apps and cloud services, while Microsoft 365 adds identity, security, device management, and in some plans Windows licensing benefits.

What changed since the original Office 365 comparison

Many plan names from older contracts still appear in customer portals, invoices, and renewal discussions, but Microsoft has renamed and repackaged much of the lineup since 2018. The biggest change is that Microsoft 365 is now the broader platform: Microsoft 365 can include Office apps, Exchange, SharePoint, OneDrive, Teams availability, Microsoft Entra ID, Microsoft Intune, Microsoft Defender, Microsoft Purview capabilities, and Windows benefits depending on the plan. Office 365 still exists, especially in Enterprise plans such as Office 365 E1, E3, and E5, but it is more focused on productivity and collaboration services.

Quick answer: Microsoft 365 vs Office 365

Choose Office 365 when you primarily need email, Office apps, file storage, and collaboration services. Choose Microsoft 365 when you also need security controls, identity protection, device management, endpoint protection, compliance capabilities, or Windows Enterprise/Business benefits.

In practical terms: Microsoft 365 Business Standard is the modern successor to the old Office 365 Business Premium plan. Microsoft 365 Business Premium is the security and management bundle most small and midsize businesses should evaluate when they need Conditional Access, Intune device management, Defender for Business, and stronger identity protection.

Old plan names mapped to current names

Older name	Current name or closest current equivalent	Notes
Office 365 Business Essentials	Microsoft 365 Business Basic	Web and mobile apps, business email, OneDrive, SharePoint, and collaboration services.
Office 365 Business Premium	Microsoft 365 Business Standard	Adds desktop Office apps to the Business Basic-style service bundle.
Microsoft 365 Business	Microsoft 365 Business Premium	Adds security, device management, identity protection, and Windows Business benefits.
Office 365 Business	Microsoft 365 Apps for business	Office desktop apps and OneDrive, without business email.
Office 365 ProPlus	Microsoft 365 Apps for enterprise	Enterprise Office apps subscription, commonly used with larger organizations and Enterprise plans.
Azure Active Directory	Microsoft Entra ID	Microsoft renamed Azure AD to Microsoft Entra ID.
Microsoft Endpoint Manager	Microsoft Intune	Intune is the current name used for endpoint and mobile device management.

Current Microsoft 365 and Office 365 plan comparison

Plan	Best fit	Office desktop apps	Business email	Security and device management	User limit guidance
Microsoft 365 Apps for business	Users who need Office apps and OneDrive only	Yes	No	Basic account security; no Intune or advanced identity bundle	Business plan, up to 300 users
Microsoft 365 Business Basic	Small businesses needing cloud email and web apps	Web/mobile only	Yes	Basic security; advanced controls require add-ons or higher plan	Up to 300 users
Microsoft 365 Business Standard	Small businesses needing email plus desktop Office apps	Yes	Yes	Collaboration-focused; does not include Intune, Entra ID Plan 1, or Defender for Business	Up to 300 users
Microsoft 365 Business Premium	Security-focused SMBs	Yes	Yes	Includes Microsoft Intune, Microsoft Entra ID Plan 1 capabilities such as Conditional Access, Microsoft Defender for Business, and Windows Business benefits for qualifying devices	Up to 300 users
Office 365 E1	Enterprise users needing web apps, email, and services	Web/mobile only	Yes	Productivity-focused; security and device management usually require add-ons or Microsoft 365 Enterprise	Enterprise
Office 365 E3	Enterprise productivity standard	Yes	Yes	Stronger productivity and compliance baseline than Business Standard, but not the same as Microsoft 365 E3 for identity, endpoint, and Windows	Enterprise
Office 365 E5	Enterprise productivity plus advanced communication, security, and compliance features	Yes	Yes	Adds more advanced Office 365 security/compliance capabilities, but still differs from Microsoft 365 E5	Enterprise
Microsoft 365 E3	Enterprise suite for productivity, identity, endpoint management, and Windows Enterprise	Yes	Yes	Includes Office 365 E3-style productivity, Microsoft Intune, Microsoft Entra ID Plan 1, and Windows Enterprise E3 benefits	Enterprise
Microsoft 365 E5	Enterprise suite for advanced security, compliance, analytics, and identity protection	Yes	Yes	Adds advanced Microsoft Defender, Microsoft Purview, and Microsoft Entra capabilities beyond E3	Enterprise

Microsoft 365 Business Standard vs Microsoft 365 Business Premium

The most common SMB decision is Business Standard versus Business Premium. Business Standard is mainly a productivity plan: email, Teams availability where licensed, SharePoint, OneDrive, and the installed Microsoft 365 apps. Business Premium includes those productivity capabilities and adds the controls many organizations now need for cyber insurance, remote work, and compliance readiness.

Business Premium is usually the better fit when you need: Conditional Access policies, enforced MFA based on risk or location, device compliance rules, mobile application management, Windows and macOS device enrollment, remote wipe for lost devices, Microsoft Defender for Business endpoint protection, phishing and malware protection improvements, and Microsoft Purview Information Protection features such as sensitivity labels and data protection controls. It also includes Windows 11 Business benefits for licensed users on qualifying Windows Pro devices.

Business Standard can still be a good fit for very small organizations with simple requirements, but it often needs security add-ons later. If you expect to manage laptops, restrict access from unmanaged devices, or standardize endpoint protection, Business Premium is usually the cleaner licensing path.

Office 365 E3 vs Microsoft 365 E3

Office 365 E3 and Microsoft 365 E3 are often confused because both include the Microsoft 365 apps and enterprise cloud services. The difference is scope.

Office 365 E3 is primarily a productivity and collaboration license. It includes enterprise email, Office apps, SharePoint, OneDrive, and core compliance capabilities. It does not, by itself, provide the full identity, endpoint management, and Windows Enterprise bundle that many enterprises need.

Microsoft 365 E3 includes the Office 365 E3 productivity foundation plus Enterprise Mobility + Security capabilities and Windows Enterprise E3 benefits. That means Microsoft Intune, Microsoft Entra ID Plan 1 capabilities such as Conditional Access, endpoint management, and broader enterprise security controls are part of the suite. If you are standardizing device management, Zero Trust access policies, or Windows Enterprise, compare Microsoft 365 E3 rather than Office 365 E3 alone.

300-user limit: when Business plans stop being enough

Microsoft 365 Business Basic, Business Standard, Business Premium, and Microsoft 365 Apps for business are designed for organizations with up to 300 users per plan. If you are close to that limit, need advanced compliance, have complex identity requirements, require enterprise voice or security features, or operate across multiple regions with stricter governance, evaluate Enterprise plans such as Office 365 E3/E5 or Microsoft 365 E3/E5.

Some organizations mix plan families carefully, but licensing combinations should be reviewed before purchase. Add-ons, compliance requirements, Teams availability, Copilot eligibility, and security baselines can change the best answer.

Teams licensing and regional availability

Microsoft Teams packaging has changed in recent years and can vary by region, customer type, and purchasing channel. In some markets, Microsoft 365 and Office 365 suites are sold in versions with Teams and versions without Teams; in other cases, Teams may be purchased as a separate add-on. Existing customers may also have renewal options that differ from new purchases.

Before buying or renewing, confirm the current Teams rules for your tenant region, license program, and subscription term. This is especially important for Enterprise plans, multinational organizations, and customers moving from older Office 365 bundles.

Licensing notes for CSP and New Commerce Experience

Most commercial Microsoft 365 subscriptions purchased through Cloud Solution Provider partners now follow Microsoft New Commerce Experience terms. Key points to plan for: monthly subscriptions provide more flexibility but usually cost more than annual commitments; annual subscriptions can often be billed monthly or upfront but still commit you for the full term; seat increases are generally allowed during the term; seat reductions and cancellations are limited to a short cancellation window after purchase or renewal; and upgrades may be possible but should be planned before renewal.

Because licensing rules, promotions, and product availability can change, review your renewal dates, add-ons, and commitment terms before making changes. This is especially important when moving from Business Standard to Business Premium, from Office 365 E3 to Microsoft 365 E3, or when adding Microsoft 365 Copilot.

Microsoft 365 Copilot readiness

Microsoft 365 Copilot is an add-on, not a replacement for the base Microsoft 365 or Office 365 license. Eligibility has expanded across many commercial plans, including common Business, Apps, Office 365 Enterprise, and Microsoft 365 Enterprise licenses, but you should verify current eligibility at the time of purchase.

Before deploying Copilot, review more than the license checkbox. Confirm that users have Microsoft Entra ID accounts, current Microsoft 365 apps, properly configured Exchange, OneDrive, SharePoint, and Teams services where needed, and appropriate security controls. Most importantly, clean up data access. Copilot can surface information users are already permitted to access, so permissions, sensitivity labels, retention, data loss prevention, external sharing, and access reviews should be addressed before a broad rollout. A pilot with training and adoption planning usually produces better results than simply assigning licenses to everyone.

Which plan should you choose?

Scenario	Recommended direction
Very small business needing email and browser-based apps	Start with Microsoft 365 Business Basic.
Business needing installed Office apps and email but limited security needs	Microsoft 365 Business Standard.
SMB needing MFA policies, device management, endpoint protection, and better security	Microsoft 365 Business Premium.
Organization with deskless or frontline workers	Evaluate Microsoft 365 Frontline plans and confirm Teams, device, and compliance needs.
Organization above 300 users or with enterprise compliance requirements	Compare Office 365 E3/E5 and Microsoft 365 E3/E5.
Enterprise needing endpoint management and Windows Enterprise	Microsoft 365 E3 or E5 is usually a better fit than Office 365 E3 alone.
Organization preparing for Copilot	Choose an eligible base license, then review identity, security, permissions, and data governance before deployment.

Key takeaways

• Office 365 is now best understood as the productivity and collaboration layer; Microsoft 365 is the broader suite that can add identity, security, endpoint management, compliance, and Windows benefits.
• Office 365 Business Premium is now Microsoft 365 Business Standard, while the old Microsoft 365 Business plan is now Microsoft 365 Business Premium.
• Microsoft 365 Business Premium is the key SMB upgrade when you need Microsoft Intune, Microsoft Entra ID Plan 1 capabilities, Conditional Access, Defender for Business, and managed endpoints.
• Office 365 E3 is not the same as Microsoft 365 E3; Microsoft 365 E3 adds enterprise identity, device management, and Windows Enterprise benefits.
• Business plans generally have a 300-user limit, so larger or more regulated organizations should evaluate Enterprise plans.
• Teams packaging, CSP/NCE commitment terms, and Copilot eligibility should be checked before purchase or renewal.

Need help choosing the right Microsoft 365 plan, upgrading from Office 365, or preparing for Copilot? IT Partner can review your tenant, licensing, security baseline, and renewal terms, then recommend a practical path through Microsoft 365, Business Premium, cybersecurity, and managed IT services.