The domain in the form <name>.onmicrosoft.com that each Entra tenant receives at creation; it cannot be deleted or altered.
Also called onmicrosoft.com domain.
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Terms in this definition
- Domain
A way of grouping workspaces by area of the business, in support of a data mesh approach. Items take on their workspace's domain, letting you filter the OneLake catalog by it, and certain tenant settings can be passed to domain admins; domains have no effect on access permissions.
- Tenant
A trusted, dedicated Microsoft Entra ID instance that stores the users, groups and app registrations of one organisation. A subscription trusts only a single tenant, although a tenant can be trusted by several subscriptions.
Related terms
- Custom domain name
A DNS domain you own, contoso.com for example, added to a Microsoft Entra tenant next to the permanent onmicrosoft.com initial domain. Users can sign in with it once you have proved ownership through a TXT or MX record.
- Fallback domain
When a Microsoft 365 organisation signs up, it gets an onmicrosoft.com domain that serves as the default for usernames and mail routing. You can switch the fallback role to a different onmicrosoft.com domain, but these domains can never be deleted and each tenant may hold at most five of them.
- Microsoft Entra tenant
Instance of the Entra ID directory dedicated to an organisation, with an initial .onmicrosoft.com domain picked when it is created. Every Azure subscription trusts one tenant only.