Microsoft 365

Personal covers one named user across all of their devices; Family extends the same apps to up to six people, each with their own OneDrive and mailbox. The Business SKUs (Basic, Standard, Premium, Apps for Business) target organisations up to 300 seats and unlock shared mailboxes, custom domains, admin controls and the Microsoft 365 admin center. Above 300 seats — or whenever you need advanced compliance, Microsoft Intune, conditional access, Entra ID P1 or P2, eDiscovery Premium or the full Defender suite — you cross into Enterprise plans (E1, E3, E5, plus Frontline F1/F3 for shift workers). Enterprise plans have no per-tenant seat cap and are the only SKUs that include Windows 11 Enterprise as a per-user entitlement.

Apps for Business and Apps for Enterprise give you only the desktop and web Office apps (Word, Excel, PowerPoint, Outlook, OneNote, Access on Windows) without Exchange Online mail. Business Basic flips the trade-off: Exchange Online, Teams, SharePoint and OneDrive, web-only Office. Business Standard combines both, which is the most common SMB choice. Business Premium adds Defender for Business, Intune device management, conditional access and basic information protection — the natural fit for organisations without a separate security stack. Enterprise E3 adds Entra ID P1, Azure Information Protection P1, Office LTSC-equivalent rights, and the larger 100 GB mailbox; E5 layers on Defender for Office 365 Plan 2, Defender for Endpoint Plan 2, Entra ID P2, eDiscovery Premium, Customer Lockbox, Power BI Pro and the audio-conferencing dial-in for Teams.

All Microsoft 365 subscriptions are user-based: one licence covers the same person across up to five PCs or Macs, five tablets and five phones, for a total of fifteen activations. Licences can be reassigned between users, but not faster than every 90 days per Microsoft Product Terms — reassigning a Microsoft 365 licence daily to rotate it across staff is a documented audit finding, not a clever cost trick. For shared-device scenarios (call centres, factory floors, retail), use shared device activation mode, which authenticates each user fresh and does not count against the 5+5+5 limit.

Most organisations buy Microsoft 365 through a CSP partner rather than directly from Microsoft. The CSP handles billing, scales seats up or down monthly, provides level-1 support, can mix annual and monthly commitments, and often bundles managed services such as tenant configuration, security baselines and adoption coaching. New Commerce Experience (NCE) terms apply: monthly subscriptions cost roughly 20% more than annual ones, and annual commitments cannot be reduced mid-term — only at renewal. Plan seat counts conservatively at renewal time and use monthly subscriptions for genuinely seasonal hires.

Microsoft 365 Copilot is a separate per-user add-on, sold annually, that requires an underlying eligible Microsoft 365 subscription (Business Standard / Premium, E3 / E5, A3 / A5, F1 / F3 and several others). It enables Copilot in Word, Excel, PowerPoint, Outlook, Teams and the Microsoft 365 Copilot chat surface, with data-handling commitments that keep prompts and responses inside the tenant boundary. Before deploying Copilot, the practical prerequisites are healthy SharePoint permissions (Copilot exposes whatever a user already has access to), labelled sensitive content (so the model can respect classification), and an Entra ID baseline with conditional access.

Frontline plans (F1, F3) target shift workers, retail staff and field technicians who do not need a full Office desktop install but do need email, Teams and a managed identity. They include web and mobile Office, Exchange with a 2 GB mailbox, Teams, SharePoint, Intune (F3) and Defender for Endpoint Plan 1 (F3) at a substantially lower price than knowledge-worker plans. Education plans (A1, A3, A5) mirror the Enterprise tier with academic pricing and education-specific features such as Microsoft Education Insights and the free Minecraft Education entitlement.

Microsoft 365 Apps and a perpetual Office 2024 install can coexist on the same machine in narrow edge cases (e.g. Visio perpetual alongside Microsoft 365 Apps), but it is rarely a good idea — they share registry hives and Click-to-Run update channels. The supported pattern is to pick one or the other on a given device. If you genuinely need an offline, one-time-purchase, no-cloud Office for regulated machines, Office LTSC 2024 via Volume Licensing is the documented option; everything else benefits from the subscription.