What should I use to add Microsoft login to a B2B app?

If you want Microsoft login for a B2B app, the usual choice is:

Use Microsoft Entra ID (formerly Azure AD)

Best fit when:

• Your users are from other organizations
• You want companies’ employees to sign in with their work Microsoft accounts
• You need enterprise SSO, access control, and tenant-based authentication

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Typical options

1. Microsoft Entra ID

Use this for:

• Internal business users
• External users from partner companies
• Single-tenant or multi-tenant B2B sign-in

2. Microsoft Entra External ID

Use this if your app is more of a customer/partner-facing app and you want broader external identity support, including non-Microsoft identities.

3. Microsoft personal accounts

If you mean users signing in with:

• @outlook.com
• @hotmail.com
• Microsoft consumer accounts

then you’d support personal Microsoft accounts too, but that’s usually not the main B2B path.

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What to implement

For most B2B apps, you’d use:

• OpenID Connect
• OAuth 2.0
• Microsoft identity platform / Entra ID endpoints

Common libraries:

• MSAL for Microsoft auth
• Platform SDKs for your stack:
  • MSAL.js
  • MSAL.NET
  • MSAL Python
  • MSAL Java
  • MSAL Node

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Recommendation

If your app is truly B2B, start with:

Microsoft Entra ID + OpenID Connect + MSAL

If you want, I can also tell you:

• whether to choose single-tenant vs multi-tenant
• how to set this up in React, Node, .NET, or Python
• whether you need Entra External ID instead