Business Premium vs Office E5

Question

Does the business premium license include all the functionality of the "old" E5 license, specifically wrt security if the Defender and Purview bolt-on, as well as SOC and MDR is added

Answer 1

Microsoft 365 Business Premium does not include all the functionality of the “old” Microsoft 365 E5 license, even when adding the available security add-ons.

From the context:

1. Business Premium base capabilities
   • Business Premium is designed for small and medium-sized businesses (up to 300 users) and includes:
     • Microsoft Defender for Business (endpoint security)
     • Microsoft Defender for Office 365 Plan 1
     • Full Intune capabilities for device and app management
   • It does not include the full Microsoft 365 E5 security and compliance stack by default.
2. E5 / E5 Security suite capabilities
   • Microsoft 365 E5 includes a broader security and compliance suite, including:
     • Microsoft Defender for Office 365 Plan 2
     • Microsoft Defender for Endpoint
     • Microsoft Entra ID Plan 2
     • Microsoft Defender for Identity
     • Microsoft Defender for Cloud Apps
     • Microsoft Purview advanced capabilities such as Customer Lockbox, Customer Key, eDiscovery (Premium), Audit (Premium), and other Purview Suite features.
   • These are explicitly called out as part of E5 in the plan options and platform service descriptions.
3. Business Premium + Defender Suite / E5 Security add-on
   • Business Premium customers can add the Microsoft Defender Suite (formerly Microsoft 365 E5 Security) as an add-on.
   • This add-on “up levels” security with more protection for identities, devices, email, files, and apps, and includes components such as:
     • Microsoft Entra ID Plan 2
     • Microsoft Defender for Identity
     • Microsoft Defender for Endpoint Plan 2
     • Microsoft Defender for Office 365 Plan 2
     • Microsoft Defender for Cloud Apps
   • This combination (Business Premium + Defender Suite/E5 Security) brings the security stack closer to what is in Microsoft 365 E5 from a threat protection perspective.
4. What is not stated as equivalent
   • The context does not state that Business Premium + Defender Suite/E5 Security is fully equivalent to Microsoft 365 E5 overall.
   • In particular, E5 includes additional Microsoft Purview compliance and information protection capabilities (for example Customer Lockbox, Customer Key, eDiscovery (Premium), Audit (Premium), and the broader Purview Suite) that are not listed as part of Business Premium or the Defender Suite add-on in the provided material.
   • SOC/MDR services (managed detection and response, security operations center services) are not described in the context as being included with either Business Premium or the Defender Suite/E5 Security add-on.

Based on the provided information, Business Premium plus the Defender Suite/E5 Security add-on significantly enhances security and brings many E5-level security components, but it is not described as a complete functional replacement for the full Microsoft 365 E5 license, especially regarding the broader Purview compliance features and any SOC/MDR services.

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References:

• Microsoft 365 Business Premium frequently asked questions
• Microsoft 365 Business Premium security - frequently asked questions
• What's new in security in Microsoft 365 for business
• Microsoft 365 and Office 365 platform service description
• Built-in security features for cloud mailboxes service description
• Microsoft 365 and Office 365 plan options
• March 2025 announcements