Request to Unblock Guest Invitations in Microsoft Entra ID

Question

Request to Unblock Guest Invitations in Microsoft Entra ID

KWS角田恭章 0

Dear Microsoft Support Team,

We are experiencing an issue with guest user invitations in our Microsoft Entra ID tenant.

We attempted to invite more than 100 external users in bulk through the Microsoft Entra admin center (Azure Portal). After performing this bulk invitation, the following error message appeared, and we are no longer able to invite external users.

Error message:

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

Details:

Invitation method: Bulk invitation through the Microsoft Entra admin center

Number of users: More than 100

Purpose: Inviting external users for legitimate business purposes

Impact: All subsequent guest invitation attempts are blocked.

These invitations were initiated for legitimate business purposes. We believe that our tenant may have been automatically restricted by Microsoft's security mechanisms due to the volume of invitations.

We kindly request that you investigate this issue and remove the restriction on guest invitations for our tenant.

Please let us know if you require any additional information, such as our Tenant ID, Correlation ID, or the date and time of the incident.

Thank you for your assistance.

Best regards,

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1 answer

Your answer

Answer 1

Hi @KWS角田恭章

The error “Invitations are blocked for this directory due to suspicious activity” indicates that Microsoft’s automated security system has restricted guest invitations at the tenant level. This can occur when a large number of external invitations are sent within a short period, even when the invitations are for legitimate business purposes.

Since the message explicitly states that invitations are blocked for the directory due to suspicious activity, this issue will need to be reviewed by Microsoft Support. Please ask your Global Administrator (IT administrator) to raise a support request through Microsoft 365 admin center > Support > Help & support for further investigation.

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

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A technical support engineer can perform a remote session to investigate the situation, verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis.

Your 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.

When contacting Microsoft Support, please provide:

Your Tenant ID
The complete error message
The date and approximate time the issue occurred
The number of guest invitations sent
The method used to send the invitations
Any available Correlation ID, Request ID, or screenshot
Confirmation that the invitations were sent for legitimate business purposes

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.