title: Implementing Office 365 single sign-on using custom authentication/claims provider in ADFS 3.0 (RE: AADSTS90019)
body: <p>I have a new Claims Provider Trust successfully configured in ADFS 3.0 that allows us to use a separate SAML IdP and let ADFS 3.0 be the SP. We now see "You are signed in" when we go through our SAML IdP. So this part works fine (SSO into ADFS 3.0).</p>
  
  <p>However, attempting to access Office 365 apps now returns the following error by at <a href="https://login.microsoftonline.com/login.srf" rel="nofollow">https://login.microsoftonline.com/login.srf</a>:</p>
  
  <blockquote>
    <p>AADSTS90019: No tenant-identifying information found in either the
    request or implied by any provided credentials.</p>
  </blockquote>
  
  <p>Any ideas? Do I need to add a Relying Party Trust to get Office 365 to also trust our SAML-based Claims Provider?</p>
  
  <p>Trying to complete this last leg in getting fully SSO-ed into Outlook Web App, for example, and feel like I'm just a couple parameters away.</p>