Invitations are blocked for this directory due to suspicious activity. Please contact Microsoft support for help.

Graph POST /invitations had been succeeding until today. Bulk inviting users is important for us to enable federated SSO into our platform for large agencies (some have users in the range of 500-1000 users). I'm happy to adjust our code to add a sleep timer if invitations were sent too quickly, but we need this unblocked for our platform to successfully onboard agencies.

Full error message:

Graph POST /invitations returned 403: {"error":{"code":"Forbidden","message":"Invitations are blocked for this directory due to suspicious activity. Please contact Microsoft support for help.","innerError":{"request-id":"429f1932-ad0d-4d4f-bdc2-f2bc6cc9b1bb","date":"2026-06-05T18:55:07","client-request-id":"429f1932-ad0d-4d4f-bdc2-f2bc6cc9b1bb"}}}

This seems to be a common issue so I'm disappointed with how aggressive these fraud detection policies are against valid business cases:

https://learn.microsoft.com/en-in/answers/questions/5846024/microsoft-graph-invitation-returns-403-invitations

https://learn.microsoft.com/en-au/answers/questions/5818183/invitations-are-blocked-for-this-directory-due-to

CC @Raja Pothuraju