M365 Add-on Architecture — Base Requirements, Stacking Rules & Every Add-on Mapped
Master M365 add-on licensing: which base licenses unlock which add-ons, stacking rules, and a complete map of security, compliance, communication, AI, and productivity add-ons with pricing.
Key Facts
- Add-ons require specific base licenses — you cannot purchase Copilot for Microsoft 365 ($30/user/month) without an underlying E3, E5, Business Standard, or Business Premium license.
- Security add-ons follow a tiered progression: Defender for Office 365 P1 is in E3, P2 is in E5 or available as a standalone add-on (~$5/user/month). They do not replace each other — P2 includes all P1 capabilities.
- Teams Phone Standard ($8/user/month) requires an E3/E5 or Business plan as a base, plus a Calling Plan or Direct Routing/Operator Connect for PSTN connectivity.
- Audio Conferencing ($4/user/month) is bundled in E5 but is a paid add-on for E3, Business Standard, and Business Premium. It enables dial-in phone numbers for Teams meetings.
- Microsoft Intune Plan 1 is included in E3/E5 and Business Premium. Intune Plan 2 ($4/user/month) and the Intune Suite ($10/user/month) add advanced endpoint management, privilege management, and remote help.
- Copilot for Microsoft 365 at $30/user/month is the most expensive mainstream add-on — it requires an E3/E5/Business Standard/Premium base and provides AI assistance across Word, Excel, PowerPoint, Outlook, and Teams.
- Exchange Online Plan 1 ($4/user/month, 50 GB) and Plan 2 ($8/user/month, 100 GB with archiving) can be purchased standalone without any Microsoft 365 suite — useful for mailbox-only scenarios.
- The Viva Suite ($12/user/month) bundles Viva Insights, Viva Learning, Viva Engage, Viva Goals, and Viva Pulse — individual Viva modules are available separately at $2–6/user/month each.
How Add-Ons Work in Microsoft 365
Add-ons extend the capabilities of a base M365 license. Think of them as specialized modules you plug into your foundation plan. The critical thing to understand: every add-on has a list of qualifying base plans. Buy the wrong base, and the add-on will not activate. Planning add-ons is best done before your Microsoft 365 migration — not after. Getting the base license and add-on structure right from day one avoids costly relicensing later.
Microsoft enforces these prerequisites technically — you literally cannot assign an add-on license to a user who lacks the required base license in the Admin Center.
Security Add-Ons
Microsoft Defender for Office 365
- Plan 1 ($2/user/mo) — Safe Links, Safe Attachments, anti-phishing. Included in E3.
- Plan 2 ($5/user/mo) — Plan 1 + Threat Explorer, automated investigation, attack simulation. Included in E5.
Microsoft Defender for Endpoint
- Plan 1 — Next-gen anti-malware, device control, attack surface reduction. Included in E3.
- Plan 2 ($5.20/user/mo add-on) — Plan 1 + EDR, threat analytics, sandbox. Included in E5.
Identity Protection
- Entra ID P1 — Conditional Access, MFA, self-service password reset. Included in E3.
- Entra ID P2 ($9/user/mo add-on) — P1 + PIM, Identity Protection, access reviews. Included in E5.
- Entra ID Governance ($7/user/mo) — Lifecycle workflows, entitlement management. Separate add-on.
Compliance Add-Ons
- Microsoft Purview Compliance Manager — Included in E3/E5 at different capability levels.
- Information Protection & Governance ($10/user/mo) — Auto-labeling, trainable classifiers, records management.
- Insider Risk Management ($10/user/mo) — Detect and act on risky user activity patterns.
- eDiscovery Premium — Included in E5. Advanced hold, review sets, machine learning culling.
- Exchange Online Archiving ($3/user/mo) — Unlimited archive mailbox. Required for heavy email users on E3.
If your organization is migrating from on-premises Exchange to Microsoft 365, plan your compliance add-ons before cutover. Archive mailboxes should be provisioned during migration so historical email flows directly into the online archive — not into the primary mailbox where it counts against your quota.
Communication Add-Ons
- Teams Phone Standard ($8/user/mo) — Cloud PBX, call queues, auto-attendants. Included in E5.
- Teams Phone with Calling Plan ($15/user/mo) — Phone Standard + domestic calling minutes.
- Audio Conferencing ($4/user/mo) — Dial-in numbers for Teams meetings. Included in E5.
- Teams Premium ($10/user/mo) — AI-powered meeting recaps, custom branding, advanced webinars.
AI & Analytics Add-Ons
- Microsoft 365 Copilot ($30/user/mo) — AI assistant in Word, Excel, PowerPoint, Outlook, Teams. Requires E3/E5/Business Standard/Premium.
- Copilot Studio ($200/mo tenant-level) — Build custom copilots with GPT Builder and connectors.
- Power BI Pro ($10/user/mo) — Interactive dashboards and reports. Included in E5.
- Power BI Premium Per User ($20/user/mo) — Pro + paginated reports, deployment pipelines, AI insights.
- Power Automate Premium ($15/user/mo) — Attended RPA, AI Builder credits, premium connectors.
Pro Tip
Before buying Copilot licenses for your entire organization, run a pilot with 10-20 power users. Copilot's value varies dramatically by role — executives and content creators see the biggest gains, while data entry roles may see minimal benefit.
Device & Productivity Add-Ons
- Intune Suite ($10/user/mo) — Advanced endpoint management: remote help, tunnel, firmware-over-the-air.
- Microsoft Viva Suite ($12/user/mo) — Employee experience: Insights, Learning, Engage, Goals, Pulse.
- Windows 365 Enterprise ($28.50+/user/mo) — Cloud PC. Price varies by CPU/RAM/storage config.
- Universal Print ($4/user/mo) — Cloud-based print management. No print servers needed.
- Visio Plan 2 ($15/user/mo) — Flowcharts, org charts, floor plans. Desktop + web.
- Project Plan 3 ($30/user/mo) — Project management. Desktop app + Project for the web.
- Project Plan 5 ($55/user/mo) — Plan 3 + Portfolio management, demand management, resource management.
Did You Know?
Add-ons require specific base licenses — you cannot purchase Copilot for Microsoft 365 ($30/user/month) without an underlying E3, E5, Business Standard, or Business Premium license.
Test Your Knowledge
Question 1 of 4
A Business Standard user wants to use Copilot for Microsoft 365. What is the total per-user monthly cost?
Chapter Summary
- 1Microsoft organizes add-ons into families: Security (Defender suite), Compliance (Purview suite), Communication (Teams Phone, Audio Conferencing, Teams Premium), AI (Copilot, Copilot Studio), Device Management (Intune Suite), and Productivity (Viva, Project, Visio).
- 2The base license determines which add-ons you can attach. Business plans unlock a smaller set of add-ons than Enterprise plans — for example, you cannot add Microsoft Purview Insider Risk Management to a Business Premium plan.
- 3Stacking rules allow multiple add-ons on the same user, but you cannot stack two versions of the same product (e.g., Defender P1 + Defender P2 separately — P2 already includes P1). Always check the supersession hierarchy.
- 4Standalone services like Exchange Online Plan 1/2, SharePoint Online Plan 1/2, and OneDrive for Business Plan 1/2 are available independently and are commonly used for mailbox-only users, shared mailboxes, or file storage without a full Microsoft 365 suite.
- 5Windows 365 ($20–$158/user/month depending on SKU) is technically an add-on that provisions Cloud PCs. It requires Entra ID and Intune — but does not require an E3 or E5 base, making it semi-independent.
- 6Project Plan 1 ($10/user/month), Plan 3 ($30/user/month), and Plan 5 ($55/user/month) can be added to any Microsoft 365 base. Visio Plan 1 ($5/user/month) and Plan 2 ($15/user/month) follow the same pattern.
- 7When budgeting add-ons, always calculate the total per-user cost: base + add-ons. An E3 user with Copilot, Teams Phone, and Intune Suite costs $36 + $30 + $8 + $10 = $84/user/month — which may justify evaluating E5 at $57 and reducing add-on spend.
Ready to Buy Microsoft 365?
Save 5% when you purchase through Medha Cloud