Azure AD - SAML with 3rd party as IDP

Charanpreet Singh 1 Reputation point

My current setup is .net web application plus Azure AD as IDP for my application. My application is a public web application where anyone can sign up and get in. We are in process of signing up a contract with one of our clients who already have their website and IDP (non-Microsoft).

Our requirement is that users login to their website, lets call it and my website as So user "A" logs into User "A" sees a button "Go to" on Once "A" click on this button, if he exists on, he sees dashboard directly but if "A" does not exist - he sees signup page.

Question: Is it possible to have SAML based trust relationship between their non-microsoft IDP and my Azure AD which acts as service provider? if yes, how is it implemented so users dont see login page and auto-login to if exists.

So users from should not see login page on If they are logged into, they should be auto-logged into

Microsoft Entra External ID
Microsoft Entra External ID
A modern identity solution for securing access to customer, citizen and partner-facing apps and services. It is the converged platform of Azure AD External Identities B2B and B2C. Replaces Azure Active Directory External Identities.
2,700 questions
Microsoft Entra ID
Microsoft Entra ID
A Microsoft Entra identity service that provides identity management and access control capabilities. Replaces Azure Active Directory.
20,048 questions
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