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

Question

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

ICCT APp 0

Hello Microsoft Support,

Tenant ID: 99c250a6-aec5---c521c90fdebd

We are experiencing a critical issue with our Azure AD tenant. All guest invitations are now failing with the following error from the Graph API:

{ "error": { "code": "Forbidden", "message": "Invitations are blocked for this directory due to suspicious activity. Please contact Microsoft support for help.", "innerError": { "request-id": "b08c0c1a-051b-482f-94ee-70dd40f81aeb", "date": "2025-07-14T05:41:22" } } }

Context of Issue: We are the Global Administrators for this tenant. As part of a planned bulk onboarding process, we used the Microsoft AZURE portal bulk invitation feature and the Graph API to invite approximately 13000 users in multiple CSV batches. These users are legitimate customers/partners for our organization who need access to our systems.

After several bulk invitation operations over a short period, all further invitations began failing—even single manual invites in the portal. The error message indicates our directory’s invitation capability is now completely blocked due to suspected abuse.

Impact:

We can no longer invite any new guests.
Our onboarding of legitimate users is fully blocked.
This is affecting critical business operations and timelines.

Request:

Please review and remove the "suspicious activity" block on our directory's invitation capability.
Please confirm any guidelines or best practices to avoid hitting this block in the future.
We can provide our invitation CSV files, details of our process, and business justification for this bulk onboarding if needed.

Request IDs for Reference:

request-id: b08c0c1a-051b-482f-94ee-70dd40f81aeb
date: 2025-07-14T05:41:22

We appreciate your urgent assistance with unblocking this functionality.

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Raja Pothuraju 47,835 Reputation points Microsoft Employee Moderator

2025-07-14T07:04:47.13+00:00
Hello ICCT APp,

As part of its security enhancements, Microsoft has anomaly detection systems in place to identify unusual activity, such as an unusually high number of invitations being sent from a tenant. If such anomalies are detected, the tenant may be temporarily blocked. For example, tenants that were created within the last 30 days can be blocked if they send 500 or more invitations within a 24-hour period.

To unblock your tenant, please provide a business justification explaining the need for bulk invitations, along with the following details:

Tenant ID or domain name

Global Administrator email address

1 answer

Your answer

Raja Pothuraju 47,835 Reputation points Microsoft Employee Moderator

2025-07-14T07:04:47.13+00:00

Hello ICCT APp,

As part of its security enhancements, Microsoft has anomaly detection systems in place to identify unusual activity, such as an unusually high number of invitations being sent from a tenant. If such anomalies are detected, the tenant may be temporarily blocked. For example, tenants that were created within the last 30 days can be blocked if they send 500 or more invitations within a 24-hour period.

To unblock your tenant, please provide a business justification explaining the need for bulk invitations, along with the following details:

Tenant ID or domain name

Global Administrator email address

Answer 1

Raja Pothuraju 47,835 Microsoft Employee Moderator

Hello ICCT APp,

Based on the error message you received it appears that was Invitations are blocked in your tenant due to suspicious activity.

We addressed this by collaborating with our internal team, who have now unblocked your tenant.

You can check and confirm whether you were able to access the tenant which was blocked.

Hope this helps. Let us know if you have any queries. Happy to assist you further.

Raja Pothuraju 47,835 Reputation points Microsoft Employee Moderator

2025-07-28T17:43:28.8866667+00:00

Hello ICCT APp,

If all your concerns have been resolved, I would greatly appreciate it if you could mark the answer as "Accepted." This helps both us and others in the community.
Raja Pothuraju 47,835 Reputation points Microsoft Employee Moderator

2025-07-31T19:41:57.2033333+00:00

Hello ICCT APp,

If all your concerns have been resolved, I would greatly appreciate it if you could mark the answer as "Accepted." This helps both us and others in the community.
Admin Call4Benefits 0 Reputation points

2026-07-24T14:15:03.1+00:00

Hello @Raja Pothuraju ,

We're facing the exact same problem. Would you mind to check and unblock those suspicious activifor for us?

Tenant ID: 1df80002-78e3-4d3f-bccb-47e59dd68927

Best regards,
Harvey