Implementing Invite Only Sign-Ups with Microsoft Entra External ID

Introduction

Microsoft Entra External ID represents a significant advancement in customer identity and access management (CIAM), providing organizations with powerful tools to manage external user identities. While this platform excels at creating seamless self-service sign-up experiences, many organizations require more controlled access to their applications. This article explores how to implement a closed community or invitation-only approach with Microsoft Entra External ID.

What is Microsoft Entra External ID?

Microsoft Entra External ID is a specialized identity and access management solution designed specifically for customer-facing scenarios. It allows organizations to:

• Securely manage external user identities (customers, partners, suppliers)

• Reduce administrative overhead through self-service capabilities

• Enhance user experience with streamlined authentication

• Support various authentication methods including email, social logins, and more

The standard implementation creates an open self-service registration process, making it extremely easy for users to create accounts. However, this openness may not be suitable for all business scenarios.

Why Implement a Closed Community Invite Only Entra External ID Tenant?

Many organizations prefer a controlled registration process for several reasons:

• Cost Management: Licensing costs can increase with unlimited user registration

• Security Considerations: Restricting access to verified individuals reduces security risks

• Application Beta Testing: Limiting access to specific testers during development phases

• Exclusive Community Building: Creating members-only access for premium services

• Compliance Requirements: Meeting regulatory obligations for user verification

Understanding the Standard Sign-Up/Sign-In (SUSI) Flow

Before implementing a closed community approach, it's important to understand the default sign-up process in Microsoft Entra External ID:

1. User initiates the sign-up flow and is prompted for email or social sign-in credentials

2. User provides their email address

3. System sends a One-Time Password (OTP) to the provided email

4. User enters the received OTP to verify ownership of the email address

5. The OnAttributeCollectionStart event is triggered, containing the user's email and form fields

6. User is directed to a custom sign-up form

7. User completes the form with required details (name, phone, etc.)

8. User submits the completed form

9. The OnAttributeCollectionSubmit event is triggered with the user's input data

10. System creates the user account in Microsoft Entra ID

This flow provides two critical interaction points: OnAttributeCollectionStart and OnAttributeCollectionSubmit — both essential for implementing a closed community approach.

Creating an Invite-Only Sign-Up Process

The key concept behind a closed community implementation is intercepting the standard flow to verify if the user's email exists in a pre-approved invitation list. Here's how to implement this approach:

Using OnAttributeCollectionStart vs OnAttributeCollectionSubmit 

Managing the Source of Truth for invited users

The real challenge is now how to have a high SLA solution to govern who can and can't access your Entra External ID tenant.

Real-World Implementation Success Stories

Our closed community approach to Microsoft Entra External ID has been successfully implemented across both government agencies and private sector organizations with exceptional results. Government departments have leveraged this solution to create secure portals for approved contractors and external stakeholders, ensuring sensitive information remains protected while streamlining collaboration. In the private sector, enterprises ranging from healthcare providers to financial institutions have implemented our invitation-only system to manage customer and partner access to premium services and restricted resources.

These production-ready implementations have consistently demonstrated significant reductions in administrative overhead while maintaining stringent security controls and compliance with industry regulations. The flexibility of our approach has allowed organizations to tailor the invitation system to their specific business requirements, whether managing a limited beta testing program or controlling access to enterprise-wide collaboration platforms.

Want To See A Production Demo

Want to see first hand how to implement a production grade invitation only Entra External ID? Contact Us to express interest or ask for a free consultation session to understand what we can provide you. Our team of identity experts can walk you through real-world implementations, demonstrate the administrative interfaces, and showcase the seamless user experience from invitation to account creation. We'll help you understand how this solution can be customized to meet your organization's specific requirements and security policies.