Stronger Security & Compliance for Microsoft 365 Business Premium

08 September, 2025 Samantha Cordell

In a move that significantly raises the bar for small and medium-sized business (SMB) security, Microsoft has announced three new add-ons for Microsoft 365 Business Premium. These enhancements bring enterprise-grade security and compliance capabilities to the SMB market, without the enterprise price tag.

These add-ons are designed to help businesses strengthen their security posture, meet compliance obligations, and reduce risk, all while staying within the familiar Microsoft 365 ecosystem.

But how do these new offerings stack up against Microsoft’s enterprise-grade solutions like Microsoft 365 E5? And can they help organisations meet frameworks like the ACSC Essential Eight?

Let’s take a closer look.

Microsoft Security & Compliance Add-Ons at a Glance

Microsoft’s new offerings are designed to help businesses strengthen their security posture, meet compliance obligations, and reduce risk, all while staying within the familiar Microsoft 365 ecosystem.

Microsoft Defender for Business Premium Add-on

Price: US$10/user/month
This suite brings together advanced threat protection tools that were previously only available to large enterprises:

Microsoft Entra ID P2: Adds identity protection and lifecycle management.
Defender for Endpoint Plan 2: Includes endpoint detection and response (EDR), attack surface reduction, and threat analytics.
Defender for Office 365 Plan 2: Enhances email and collaboration security with automation and simulation tools.
Defender for Identity: Detects identity-based threats like lateral movement and credential theft.
Defender for Cloud Apps: Provides visibility and control over cloud app usage.

Microsoft Purview for Business Premium Add-on

Price: US$10/user/month
This compliance-focused suite helps businesses protect sensitive data and manage risk:

Information Protection & DLP: Automatically classify and protect sensitive data.
Insider Risk Management: Detects risky behaviour such as mass downloads or data exfiltration.
Communication Compliance: Ensures internal and external communications meet policy standards.
eDiscovery & Audit: Simplifies investigations and provides audit trails for regulatory needs.

Defender + Purview Bundle

Price: US$15/user/month
For businesses that need both security and compliance, this bundle offers up to 68% savings compared to purchasing the tools separately.

How Does This Compare to Microsoft 365 E5?

The good news is the new Defender and Purview add-ons for Business Premium essentially mirror the capabilities of Microsoft 365 E5 Security and Compliance, but at a fraction of the cost. For example:

Defender for Endpoint Plan 2, Defender for Office 365 Plan 2, and Defender for Cloud Apps, all included in E5, are now available via the Defender add-on.
Microsoft Entra ID P2 and Defender for Identity, also part of E5, are included.
Similarly, the Purview add-on brings Insider Risk Management, eDiscovery, and Information Protection, which are core to E5 Compliance.

This means SMBs can now access E5-level protection and governance without needing to upgrade to the full enterprise suite.

Does This Help Meet ACSC Essential Eight Requirements?

Yes, with the right configuration, Microsoft 365 Business Premium plus the new Defender and Purview add-ons can help organisations meet Essential Eight Maturity Level 1 and even Level 2 requirements.

Here’s how Microsoft 365 maps to the Essential Eight:

Essential Eight Control	Microsoft 365 Tools That Support It
Patch Applications & OS	Intune + Windows Update for Business
Multi-Factor Authentication	Entra ID P2 + Conditional Access
Restrict Admin Privileges	Entra ID Governance + Role-Based Access Control (RBAC)
Application Control	Intune App Control + Windows Defender Application Control (WDAC)
Restrict Office Macros	Intune + Attack Surface Reduction (ASR) Policies
Application Hardening	Defender for Endpoint + Intune
Regular Backups	Microsoft 365 Retention + 3rd-party backup tools
Audit & Logging	Microsoft Sentinel + Purview Compliance Manager

Purview Compliance Manager also includes Essential Eight templates to automate assessments, flag gaps, and provide actionable recommendations.

Why This Matters

✅ Enterprise-Grade Protection for SMBs – These add-ons close the gap between SMB and enterprise security. Businesses can now access the same tools used by large corporations to detect threats, protect identities, and secure endpoints, without needing a dedicated security team.

✅ Simplified Compliance – With growing regulatory pressure across industries, tools like Microsoft Purview make it easier to manage data governance, retention, and privacy policies. This is especially valuable for sectors like healthcare, finance, and legal.

✅ Better Visibility and Faster Response – The Defender suite enables real-time threat detection and response, helping businesses reduce dwell time and limit the impact of security incidents.

✅ Built for the Microsoft Ecosystem – Because these tools are integrated into Microsoft 365, businesses benefit from a unified experience, no need to juggle multiple vendors or platforms.

What You Need to Know

Availability: The add-ons are available from September 2025.
Licensing: Each add-on requires a minimum of 25 users and supports up to 300 users per tenant.
Compatibility: Mixed licensing is not supported for Defender—organizations must upgrade all users to access the full suite.

Need Help Aligning with Essential Eight or Choosing the Right Microsoft 365 Add-On?

Whether you’re looking to strengthen your security posture, simplify compliance, or understand how these new tools fit into your existing Microsoft 365 environment, Diamond IT is here to help.

We can support your business by:

Mapping your environment to Essential Eight Maturity Level 1 or 2.
Configuring Microsoft 365 Defender and Purview add-ons for maximum impact.
Implementing best-practice security and compliance controls.
Providing ongoing monitoring, reporting, and support.

Talk to us today about how we can help you get the most out of Microsoft 365.