Microsoft Entra ID App Registrations

What are Entra ID App Registrations?

App Registrations in Microsoft Entra ID represent applications that are registered to interact with Microsoft 365 services using identity and permissions.

They allow apps to:

• Authenticate users
• Access Microsoft Graph APIs
• Integrate with Microsoft 365 services

👉 In simple terms: App Registrations define how applications securely connect to Microsoft 365.

How do Entra ID App Registrations Work?

When an app is registered in Entra ID:

1. Application Identity is Created
   A unique Application (Client) ID is assigned.
2. Authentication is Configured
   Using secrets, certificates, or delegated permissions.
3. Permissions are Granted
   The app is allowed to access specific APIs (e.g., Microsoft Graph).
4. Service Principal is Created
   Represents the app within the tenant for access control.

Flow:

• App requests access
• Entra ID authenticates it
• Permissions are evaluated
• Access is granted or denied

Key Features of Entra ID App Registrations

• Unique App Identity – Each app gets a Client ID
• API Permissions Management – Control access to Microsoft Graph
• Authentication Methods – Supports secrets and certificates
• Multi-Tenant Support – Apps can be used across multiple tenants
• Integration Capability – Enables automation and app integrations

Use Cases for Entra ID App Registrations

• Automation Scripts (Graph PowerShell)
• Custom Applications accessing Microsoft 365
• Third-Party App Integrations
• Daemon/Background Services
• API-Based Data Access and Reporting

Fetching Entra ID App Registrations Using PowerShell

Get-MgApplication

Retrieves all App Registrations in Microsoft Entra ID.

Creating Entra ID App Registrations Using PowerShell

⚠️ Note: Microsoft Graph PowerShell is required to create App Registrations.

Example:

New-MgApplication -DisplayName "My Test App"

This creates a new App Registration with the specified name.

Frequently Asked Questions

1. What is the difference between App Registration and Service Principal?
   App Registration defines the app globally, while the Service Principal represents it within a tenant.
2. Are App Registrations required for automation?
   Yes, they are commonly used for scripts and applications accessing Microsoft Graph.
3. Can App Registrations be multi-tenant?
   Yes, apps can be configured to work across multiple tenants.
4. Where are App Registrations managed?
   They are managed in Microsoft Entra ID (Azure Portal or PowerShell).