Unblock after getting error "Invitations are blocked for this directory due to suspicious activity

Question

Unblock after getting error "Invitations are blocked for this directory due to suspicious activity

Orlando Carvajal 26

Yesterday, while migrating about 130 external users from one directory to another. I did a Bulk Invite and it only added 100 users. For the remaining users I got errors like:

"Request was unsuccessful. Details: Invitations are blocked for this directory due to suspicious activity. Please contact Microsoft support for help."

Now when I try inviting a user individually, I get an error "Insufficient privileges to complete the operation". Even though I'm a Global Admin.

Can someone from Microsoft please contact me to unblock this process?

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Sridevi Machavarapu 33,820 Reputation points Microsoft External Staff Moderator

2025-11-26T01:14:12.7833333+00:00

Hello Orlando Carvajal,

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
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Answer accepted by question author

Adam Zachary 2,265

I remember this happening to one of our customers when we were helping them move a large number of external users into a new directory. Once they pushed out a big batch of guest invitations, Microsoft’s security system flagged it as unusual activity and automatically put a temporary block on the tenant.

After that block kicks in, all new invites fail, and you even start seeing confusing errors like ‘Insufficient privileges,’ even though nothing is wrong with your roles or permissions. It’s the service protecting the tenant, not an admin issue.

The only way to clear it, is to contact Microsoft support and provide the tenant ID, the correlation ID from the error, and a short explanation of the migration work.

Usually, after Microsoft verifies the activity was legitimate, they removed the block and everything goes back to normal.

There’s no setting in the portal to undo this yourself, so support has to lift the restriction on their side.

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1 additional answer

Sridevi Machavarapu 33,820 Reputation points Microsoft External Staff Moderator

2025-11-26T01:14:12.7833333+00:00

Hello Orlando Carvajal,

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
Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.

Answer 1

Sridevi Machavarapu 33,820 Microsoft External Staff Moderator

Hello Orlando Carvajal,

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.

If this answers your query, do click Accept Answer and Yes for was this answer helpful, which may help members with similar questions. .

Sridevi Machavarapu 33,820 Reputation points Microsoft External Staff Moderator

2025-11-26T16:11:06.49+00:00

Hello Orlando Carvajal,

If issue is resolved now, please click on Accept Answer and Yes for was this answer helpful to close this question.