Here are the usage constraints and other service limits for the Azure Active Directory (Azure AD) service.
A single user can belong to a maximum of 500 Azure AD tenants as a member or a guest. A single user can create a maximum of 200 directories.
You can add no more than 5000 managed domain names. If you set up all of your domains for federation with on-premises Active Directory, you can add no more than 2500 domain names in each tenant.
A maximum of 50,000 Azure AD resources can be created in a single tenant by users of the Free edition of Azure Active Directory by default. If you have at least one verified domain, the default Azure AD service quota for your organization is extended to 300,000 Azure AD resources. Azure AD service quota for organizations created by self-service sign-up remains 50,000 Azure AD resources even after you performed an internal admin takeover and the organization is converted to a managed tenant with at least one verified domain. This service limit is unrelated to the pricing tier limit of 500,000 resources on the Azure AD pricing page. To go beyond the default quota, you must contact Microsoft Support.
A non-admin user can create no more than 250 Azure AD resources. Both active resources and deleted resources that are available to restore count toward this quota. Only deleted Azure AD resources that were deleted fewer than 30 days ago are available to restore. Deleted Azure AD resources that are no longer available to restore count toward this quota at a value of one-quarter for 30 days. If you have developers who are likely to repeatedly exceed this quota in the course of their regular duties, you can create and assign a custom role with permission to create a limitless number of app registrations.
String-type extensions can have a maximum of 256 characters.
Binary-type extensions are limited to 256 bytes.
Only 100 extension values, across all types and all applications, can be written to any single Azure AD resource.
Only User, Group, TenantDetail, Device, Application, and ServicePrincipal entities can be extended with string-type or binary-type single-valued attributes.
A maximum of 100 users can be owners of a single application.
A user, group, or service principal can have a maximum of 1,500 app role assignments. The limitation is on the service principal, user, or group across all app roles and not on a limit on the number of assignments on a single app role.
Password-based single sign-on (SSO) app has a limit of 48 users, which means that there is a limit of 48 keys for username/password pairs per app. If you want to add additional users, see the troubleshooting instructions in Troubleshoot password-based single sign-on in Azure AD.
A user can only have a maximum of 48 apps where they have username and password credentials configured.
A maximum of 1200 entries can be added in the Application Manifest.
A non-admin user can create a maximum of 250 groups in an Azure AD organization. Any Azure AD admin who can manage groups in the organization can also create unlimited number of groups (up to the Azure AD object limit). If you assign a role to remove the limit for a user, assign them to a less privileged built-in role such as User Administrator or Groups Administrator.
An Azure AD organization can have a maximum of 5000 dynamic groups.
A maximum of 400 role-assignable groups can be created in a single Azure AD organization (tenant).
A maximum of 100 users can be owners of a single group.
Any number of Azure AD resources can be members of a single group.
A user can be a member of any number of groups. When using security groups in combination with SharePoint Online, a user can be a part of 2049 security groups in total (not only direct group memberships but also indirect group membership). When going over this limit, authentication and search results become unpredictable.
By default, the number of members in a group that you can synchronize from your on-premises Active Directory to Azure Active Directory by using Azure AD Connect is limited to 50,000 members. If you need to synch a group membership that's over this limit, you must onboard the Azure AD Connect Sync V2 endpoint API.
Nested Groups in Azure AD are not supported within all scenarios
Group expiration policy can be assigned to a maximum of 500 Microsoft 365 groups, when selecting a list of groups. There is no limit when the policy is applied to all Microsoft 365 groups.
At this time the following are the supported scenarios with nested groups.
One group can be added as a member of another group and you can achieve group nesting.
Group membership claims (when an app is configured to receive group membership claims in the token, nested groups in which the signed-in user is a member are included)
Conditional access (when a conditional access policy has a group scope)
Restricting access to self-serve password reset
Restricting which users can do Azure AD Join and device registration
The following scenarios DO NOT support nested groups:
App role assignment, both for access and for provisioning. Assigning groups to an app is supported, but any groups nested within the directly assigned group won't have access.
Group-based licensing (assigning a license automatically to all members of a group)
Microsoft 365 Groups.
A maximum of 500 transactions per second per App Proxy application
A maximum of 750 transactions per second for the Azure AD organization
A transaction is defined as a single http request and response for a unique resource. When throttled, clients will receive a 429 response (too many requests).
There's no limit to the number of applications that can be seen in the Access Panel per user regardless of assigned licenses.
A maximum of 1,000 rows can be viewed or downloaded in any report. Any additional data is truncated.
An Azure AD resource can be a member of no more than 30 administrative units.
A maximum of 100 Azure AD custom role assignments for a single principal at tenant scope.
A maximum of 100 Azure AD built-in role assignments for a single principal at non-tenant scope (such as administrative unit or Azure AD object). There is no limit for Azure AD built-in role assignments at tenant scope.
A user's ability to read other users' tenant information can be restricted only by the Azure AD organization-wide switch to disable all non-admin users' access to all tenant information (not recommended). For more information, see To restrict the default permissions for member users.
It may take up to 15 minutes or signing out/signing in before admin role membership additions and revocations take effect.