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

Hi @Dmytro Zlobodukhov

The error “Invitations are blocked for this directory due to suspicious activity” indicates that Microsoft has placed a service-side restriction on guest invitations in the affected Microsoft Entra tenants. Since the same error occurs when using the Azure portal, bulk invitations, and Microsoft Graph, this restriction cannot be resolved by changing administrator permissions or invitation settings. 

Since you cannot create a technical support request through the Azure or Microsoft Entra admin portals, please try submitting a support ticket through the Microsoft 365 admin center instead, if your organization has an eligible Microsoft 365 business subscription. 

For more details, please refer to: Get support - Microsoft 365 admin

A Global Administrator can follow these steps: 

• Sign in to the Microsoft 365 admin center. 
• Select Help & support. 
• If Support Assistant is enabled, turn it off.
• 
• Enter the complete error message. 
• Scroll down and select Contact support, then choose Phone or Email to submit your request.

In the support request, explain that: 

• Manual invitations fail in the Azure portal. 
• Bulk invitations are only partially processed. 
• Microsoft Graph returns a 403 Forbidden response. 
• Multiple tenants are affected, including QA, DEMO, STAGE, and PROD. 
• The restriction is blocking release preparation and SSO testing. 

You should also provide the affected tenant IDs, Microsoft Graph request IDs, timestamps, and the complete error response. Share this information only through the private support request and do not post tenant IDs, user email addresses, CSV files, access tokens, or diagnostic identifiers publicly in the forum. 

When submitting the ticket, you can request that all affected tenants be reviewed under the same case. However, since each directory may have been restricted separately, the support team may need to review each tenant individually. 

If you’re unsure who the Global Admin is within your organization, you can find guidance on locating them here: How do I find my Microsoft 365 admin?

Note: If you’re an end-user, please coordinate with your Office 365 Global Administrator to handle these steps. 

If your Microsoft 365 subscription was purchased through a reseller or Cloud Solution Provider, please contact that partner and ask them to open or escalate a Microsoft support request on your behalf. 

As a fellow forum user, I can only provide basic troubleshooting guidance and do not have access to internal systems to review or remove the restriction. I apologize that I cannot help further and hope the support team can resolve the issue as soon as possible.