Insights · Blog · Licensing · May 28, 2026
Multi-tenant organizations (MTOs) have long been everyday reality: corporations with subsidiaries, international sites with their own legal jurisdictions, or companies post-acquisition often run multiple Microsoft 365 tenants in parallel. Microsoft's MTO feature makes much of this sound like simplification — "one license per person." But that promise only applies to a narrow slice of licensing. For Dynamics 365 and the Power Platform, the world looks completely different.
This article explains where the "one human, one license" principle applies, where it doesn't — and which licenses you actually have to procure again in every target tenant. It addresses both decision-makers planning costs and the administrators and architects implementing the setup.
1×
Entra ID Premium travels with the user — one license per person is enough.
≥ P1
Prerequisite per MTO user (includes cross-tenant sync).
5
License families that are NOT portable between tenants.
Multi-Geo
Microsoft's recommendation over multi-tenant — when legally feasible.
Microsoft sums up the MTO licensing philosophy in a single sentence: one person needs only one license. Anyone licensed in the home tenant doesn't need a second license in the resource tenant.
That sounds like major savings — but the sentence applies exclusively to Microsoft Entra ID Premium (P1/P2) and Entra ID Governance. It is not a general licensing principle for the entire Microsoft Cloud.
This is exactly where the most expensive misconception arises in practice: many assume that a person licensed in the home tenant is automatically "co-licensed" everywhere. That's only true for the identity and access layer. As soon as the person works productively with applications — mailboxes, Teams Voice, CRM, ERP, Power Apps — each tenant must be licensed separately.
Using the Multi-Tenant Organization feature requires every participating user to hold at least a Microsoft Entra ID P1 license (or higher). That covers both MTO functionality and the underlying cross-tenant synchronization.
At the identity layer, the savings principle actually works. Anyone with Entra ID P1/P2 in the home tenant is entitled in the resource tenant — no second Premium license per person needs to be purchased.
Two important conditions apply:
For cross-tenant synchronization, what matters is where the license sits: every user in the source tenant whose identity is synchronized needs an Entra ID P1 license. The target tenant requires no additional P1 licenses for these synchronized users. The license effectively "travels" with the user from the home tenant.
For productive M365 services — Exchange Online, SharePoint, Teams — the savings principle does not apply. User accounts, identities, security groups, subscriptions, licenses and storage cannot be shared between tenants. Anyone working productively with M365 workloads in a second tenant needs a dedicated M365 license there.
A clear example is Teams Phone / Voice: in practice, assigning a Teams Phone license in the host tenant additionally requires an M365 base license (e.g. E3) in the same tenant. An external user would thus need a license in both tenants.
An MTO can include tenants in multiple countries — as long as they sit in the same cloud. MTO is available within GCC, GCC-H and DOD, but the tenants may only be located within the same cloud environment. An MTO between Commercial Cloud and GCCH is not possible.
This is where most cost traps lurk. The MTO "one human, one license" principle is purely an Entra rule. Dynamics 365 and Power Platform follow a completely different logic.
A Dynamics 365 or Power Platform license is bound to exactly one tenant (one Entra ID). It does not "travel" with the person. In a multi-tenant scenario, a licensed user can only access environments assigned to the same tenant. To access another tenant, the user must be invited as a guest and may need a separate license there.
This is where the biggest lever for licensing economics sits:
Microsoft's recommendation is therefore clear: for most companies, using multiple environments within a single tenant offers the best mix of functionality and easy administration. Multiple tenants make sense mainly for units that consciously want to separate directory and licenses.
Some products are licensed per tenant rather than per user. With multiple tenants, these are incurred multiple times accordingly:
With two tenants, you need these licenses twice over. This is routinely overlooked in budget planning.
Multi-tenant scenarios are also technically limited: per Microsoft, integrations between Customer Engagement and Finance & Operations apps cannot be implemented across tenant boundaries. In addition, Power Platform tenant-isolation settings can block incoming and outgoing cross-tenant connectors.
For cross-country scenarios, Microsoft therefore mostly recommends single-tenant with Multi-Geo: production environments can be created in different countries and regions, but remain part of the same organization-wide tenant. This keeps integrations and licensing significantly simpler.
A common real-world scenario:
Where is the license booked? In the DE tenant — where the Dynamics environment runs. The Japanese colleague is invited as a B2B guest into the DE tenant and is assigned a Dynamics 365 Sales license there.
Why not in Japan? A license purchased in the Japanese tenant is bound to Japan and cannot be used to access a DE environment, because licenses are not shared across tenants. It would simply be no use to the colleague for DE access.
The result: it stays at one Sales license — but booked and assigned in the DE tenant via the guest account. No second license in Japan, but also no portability of the Japanese license. If two separate tenants were not strictly required, single-tenant with Multi-Geo Dataverse would be the cleaner solution.
| License type | Required again in target tenant? |
|---|---|
| Entra ID P1 / P2 / Governance | No — "one human, one license" (but ≥1 Premium license must exist in the tenant) |
| Microsoft 365 / Office 365 (E3, E5) | Yes — per tenant where the user uses Exchange/SharePoint/Teams |
| Teams Phone / Voice | Yes — additionally requires an M365 base license in the host tenant |
| Dynamics 365 (Sales, Customer Service, Field Service, F&O) | Yes — tenant-bound |
| Power Platform (Power Apps, Power Automate per-user) | Yes — per tenant |
| Tenant licenses (Customer Insights/Journeys, Copilot Studio) | Yes, double — licensed per tenant |
only the identity and access layer (Entra ID Premium/Governance) is portable via MTO. Application licenses (M365, Teams Voice, Dynamics 365, Power Platform) must be procured and assigned anew in every tenant.
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FAQ
No. The principle applies exclusively to Microsoft Entra ID Premium (P1/P2) and Governance. Microsoft 365, Dynamics 365 and Power Platform are excluded.
Yes. Every user who uses the MTO feature needs at least Microsoft Entra ID P1.
Not per user — the entitlement travels with them, provided both tenants belong to your organization. The target tenant must, however, generally have at least one Premium license.
No. The entitlement applies only to tenants you own yourself. For dedicated accounts in a customer's tenant, separate licenses must be purchased.
In the source tenant: every synchronized user needs a P1 license there. The target tenant needs no additional P1 licenses for these users.
No. Dynamics 365 licenses are tenant-bound and not transferable. The user must be invited as a guest into the target tenant and licensed there.
In the German tenant (where the environment runs), via the B2B guest account. Not in the Japanese tenant.
Usually multiple environments within one tenant. A license then applies tenant-wide across all environments. Multiple tenants quickly lead to multi-licensing, especially with tenant-based products.
Among others, Dynamics 365 Customer Insights (Journeys + Data) and Copilot Studio. With multiple tenants, these are incurred multiple times.
Only to a limited extent. Integrations between Customer Engagement and Finance & Operations apps are not possible across tenants. For cross-country scenarios, Microsoft recommends single-tenant with Multi-Geo.
The MTO feature saves you the duplication of the login and security license (Entra ID Premium) — but not the duplication of usage and application licenses. As soon as an employee works productively with M365, Teams Voice, Dynamics 365 or the Power Platform in a second tenant, new licenses must be procured and assigned there.
Anyone planning costs and architecture cleanly should clarify the fundamental question early on: do we really need multiple tenants — or is a single tenant with multiple (Multi-Geo) environments enough? In most cases, the single-tenant variant is the significantly simpler path, both in licensing and in integration.
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