Microsoft licenses Microsoft 365 and Windows by user, by device, and by the wider seat-metric framework. The Admodum read on the per-user M365 plans (F3, E3, E5), the per-device Windows entitlements, the shared-device populations and the renewal-time metric disposition.
The principal Microsoft 365 commercial plans are per-user. A buyer assigns the seat to a specific user, and that user carries the entitlement across up to fifteen devices (five PCs, five tablets, five phones) for the most part. The wider plan stack at E1 (web-only), E3 (full Office desktop, Windows Enterprise, EMS E3 with Entra ID P1, Defender for Office P1), E5 (the wider E3 stack plus Defender for Endpoint, Defender for Identity, Power BI Pro, Phone System) sits at the Microsoft 365 plans spoke.
The per-user model is the default Microsoft 365 metric. The seat travels with the user, the user authenticates across the wider device pool, and the assignment is taken at the directory-level (the user object). The principal exercise rate is then the per-user feature exercise rate, not the device count.
The frontline-worker variants F1 (no Office apps; Exchange F1, Teams, SharePoint Online plan 1, Yammer, OneDrive plan 1) and F3 (browser-and-mobile Office, Exchange Online F3, Teams, SharePoint, OneDrive plan 1) sit at a lower per-user price than E1 and E3, with capped entitlements. The F-tier is per-user but the workload is typically shift-pattern and shared-device; the four-hour-per-week cap is the wider audit-relevant constraint.
Windows 11 Enterprise per-device is the principal Microsoft per-device licensing line. The buyer licenses the device, and any user signing in to that device carries the Windows Enterprise entitlement (current branch for business, long-term servicing channel where applicable, Enterprise-tier Windows features).
The per-device entitlement is the structurally cheaper path when the device-to-user ratio sits below one. A factory floor with one device per three shift-workers per day carries the device once on per-device Windows, against three seats on per-user M365 (or the seats may sit on F3 with the per-user posture).
Office Standard and Office Professional Plus are also available per-device historically; the per-device Office model is the legacy path against the per-user Office 365 cloud model. New deployments place the seat on the per-user Microsoft 365 cloud-bundled model in nearly all cases; the per-device Office surface is the back-stop on isolated environments and on specific regulated estates. The wider Windows Server per-core context sits at the Windows Server core licensing spoke.
The shared-device pattern is the principal driver of the per-device decision. A factory-floor shift with three workers per device per day, a hotel reception desk with rotating clerks, a hospital nursing station with twenty-four-hour-per-day device usage and a rotating staff pattern, a warehouse handheld-scanner pool with shift rotation: all carry the device-to-user ratio below one.
The arithmetic against the per-user alternative is direct. A device used by three shift-workers per day: per-device Windows once against three per-user M365 F3 seats. At the published price ratio the per-device path is roughly half the cost of the three F3 seats. The buyer-side artefact is the device-to-user ratio against each population.
The shared-device F-tier qualifier is structural. The F1 and F3 plans are per-user but designed for the shift-and-share use-case: shared-device sign-in patterns, kiosk-style Teams stations, browser-only Office. The wider seat-assignment hygiene framework that sits underneath the F-tier exercise rate sits at the seat assignment hygiene spoke.
The Frontline Worker plans F1 and F3 are per-user, with three principal constraints. Three-device cap: the F-tier user may carry the seat across up to three devices, against the fifteen-device entitlement on the E-tier. Browser-and-mobile-only Office on F3: no Office desktop applications, web-and-mobile only.
Two-hour-per-week or four-hour-per-week soft cap: on specific F-tier entitlements (Exchange Online F3 historically, certain F1 patterns), the workload pattern is designed for the frontline shift-pattern user. The cap is not strictly enforced as a system-level lockout in most patterns, but it is the underlying right-of-use boundary that the audit examines at the F-versus-E reconciliation.
The frontline-population boundary is the principal renewal-time read against the F-tier. The buyer-side artefact is the population-by-population usage pattern: the frontline F3 population versus the E3 or E5 knowledge-worker population, with the boundary placement and the per-population exercise rate. The wider M365 plans framework sits at the M365 plans spoke.
The per-user and per-device metrics are reconciled at audit time against the directory-and-device inventory. The audit examines four principal axes: the per-user assignment against the active-user count (the seat-by-user reconciliation), the per-device entitlement against the device inventory (the device-licence reconciliation), the F-tier population boundary against the actual usage pattern (the F-versus-E mismatch), and the shared-device population against the per-device coverage (the shared-device under-licensing).
The frequent false-positive pattern: an F3-assigned user that uses Office desktop applications (the user is structurally on E3, the F3 seat is under-licensed against the actual usage); a per-device Windows host on which a non-licensed user signs in (the per-device boundary covers the user, not the user-account; the per-device misuse is rare but exists); a per-user M365 seat assigned to a service account or shared account (the seat assignment is structurally invalid; the user must be a natural person).
The remediation pattern is twofold: the F-versus-E reconciliation against the actual exercise pattern, and the seat-assignment hygiene against the shared-account assignment. The wider audit framework sits at the SAM audit anatomy spoke.
The buyer-side artefacts to hold against the per-user-versus-per-device decision are: the per-population usage inventory (frontline, knowledge-worker, shared-device, service-account, partner-account), the device-to-user ratio per population, the per-user seat-by-feature exercise rate, the per-device licence coverage register, and the renewal-time metric disposition.
The renewal-time conversation is then a negotiation against artefacts. The publisher's renewal proposal carries the M365 seat-count across the estate; the buyer's decision is per population, against the artefacts; the F-tier and E-tier boundary, the shared-device per-device coverage, and the seat-assignment hygiene remediation are taken on shared arithmetic.
The wider engagement sits in the Microsoft practice; the aggregated reading list sits in the Microsoft knowledge hub; active renewal moments route to the Renewal Programme; active audit moments route to Audit Defence. The wider EA framework sits at the Enterprise Agreement overview; the wider Copilot economics that sit on top of the per-user M365 base sit at the Copilot seat economics spoke.
The per-user plan stack against which the per-device alternative is set.
The exercise-rate framework underneath the seat-by-population read.
The audit framework against which the per-user and per-device metrics are reconciled.
A senior Admodum Microsoft advisor will read your per-population device-to-user ratio, your F-versus-E boundary placement, your shared-device coverage and your renewal-time metric disposition on a private call. Active audit moments route to Audit Defence.