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.

Thomas Gallaway 25

Hi microsoft Q&A.

So while importing 281 external business users we ended up getting blocked. I created a Microsoft support ticket but they won't be able to help us until possibly monday. But we are launching this saas application on Friday night. we only are missing 46 existing customers but we want to ensure that every user is available.

We are migrating the users from OKTA via css export and I wrote a python / msgraph script that I assigned an enterprise application with the approrpirate API permissions to invite the users (without sending them a invitation email, as we will send it separately once we changed the directory from okra to Entra).

2025-10-23 21:13:47,790 - INFO - Processing user 239/285: ********@********.com
2025-10-23 21:13:47,790 - INFO - ClientSecretCredential.get_token succeeded
2025-10-23 21:13:51,152 - INFO - HTTP Request: POST https://graph.microsoft.com/v1.0//invitations "HTTP/2 201 Created"
2025-10-23 21:13:51,164 - INFO - Successfully invited user: ********@********..com (ID: **********-****-****-****-**********)
2025-10-23 21:13:51,165 - INFO - Processing user 240/285: ****@****.com
2025-10-23 21:13:51,165 - INFO - ClientSecretCredential.get_token succeeded
2025-10-23 21:13:53,365 - INFO - HTTP Request: POST https://graph.microsoft.com/v1.0//invitations "HTTP/2 403 Forbidden"
2025-10-23 21:13:53,381 - ERROR - Failed to invite user ****@****.com: 
        APIError
        Code: 403
        message: None
        message: None
        error: MainError(additional_data={}, code='Forbidden', details=None, inner_error=InnerError(additional_data={}, client_request_id='941f787c-****-****-****-982cbcc6815b', date=datetime.datetime(2025, 10, 24, 4, 13, 53), odata_type=None, request_id='b2a11418-****-****-****-8484bd08224a'), message='Invitations are blocked for this directory due to suspicious activity. Please contact Microsoft support for help.', target=None)

Sridevi Machavarapu 26,355 Reputation points Microsoft External Staff Moderator

2025-10-25T04:54:11.46+00:00
Hello Thomas Gallaway,

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.

To unblock your tenant, please provide a business justification explaining the need for bulk invitations along with below details via private message only (do not post publicly):

Tenant ID

Correlation ID from the login failure

Timestamp of the failure

Business justification
Thomas Gallaway 25 Reputation points

2025-10-25T06:32:23.14+00:00

Thank you for your prompt response and we understand the importance of protecting entra in the current day and age using anomaly detection.
Sridevi Machavarapu 26,355 Reputation points Microsoft External Staff Moderator

2025-10-25T07:27:30.73+00:00

Hello Thomas Gallaway,

I have created an incident internally with our product group team to unblock bulk invitations on your tenant. I'll share an update once they unblock it. Post that you can re-invite the users in your tenant without any blockages.
Thomas Gallaway 25 Reputation points

2025-10-25T17:00:00.85+00:00

Your help is greatly appreciated.

Answer accepted by question author

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Sridevi Machavarapu 26,355 Reputation points Microsoft External Staff Moderator

2025-10-25T04:54:11.46+00:00

Hello Thomas Gallaway,

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.

To unblock your tenant, please provide a business justification explaining the need for bulk invitations along with below details via private message only (do not post publicly):

Tenant ID

Correlation ID from the login failure

Timestamp of the failure

Business justification
Thomas Gallaway 25 Reputation points

2025-10-25T06:32:23.14+00:00

Thank you for your prompt response and we understand the importance of protecting entra in the current day and age using anomaly detection.
Sridevi Machavarapu 26,355 Reputation points Microsoft External Staff Moderator

2025-10-25T07:27:30.73+00:00

Hello Thomas Gallaway,

I have created an incident internally with our product group team to unblock bulk invitations on your tenant. I'll share an update once they unblock it. Post that you can re-invite the users in your tenant without any blockages.
Thomas Gallaway 25 Reputation points

2025-10-25T17:00:00.85+00:00

Your help is greatly appreciated.

Answer 1

Sridevi Machavarapu 26,355 Microsoft External Staff Moderator

Hello Thomas Gallaway,

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.

Thomas Gallaway 25 Reputation points

2025-10-27T07:02:16.2366667+00:00

thank you again. I am now importing the last 46 user and it is working again.
Moshe Martinez 0 Reputation points

2026-04-06T21:25:55.8966667+00:00

I have this same issue in my tenant (I got the 403 error). How can I get this resolved? We are also trying to invite about 260 external business users.
Sridevi Machavarapu 26,355 Reputation points Microsoft External Staff Moderator

2026-04-06T21:27:43.0833333+00:00

Hello Moshe Martinez,

Please create a new Q&A post at https://dotnet.territoriali.olinfo.it/en-us/answers/questions/ask/ and select the Microsoft Security | Microsoft Entra | Microsoft Entra ID tag when submitting your question and tag me over new post.

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

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