Receiving "Invitations are blocked for this directory due to suspicious activity" when attempting to invite guests"

Question

Receiving "Invitations are blocked for this directory due to suspicious activity" when attempting to invite guests"

Muhammad RIfky Ramadan 0

I encountered an issue when trying to invite guest accounts to my Azure tenant, specifically through the Microsoft 365 Admin Center, I got message "Invitations are blocked for this directory due to suspicious activity"

I am not sending invitations in bulk; instead, I invite them one by one. My requirement is likely fewer than 100 users guest invited to my business, and there is indeed a need to invite them as guest users.

Raja Pothuraju 47,165 Reputation points Microsoft External Staff Moderator

2026-03-06T07:59:58.9466667+00:00
Hello @Muhammad RIfky Ramadan,

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
Muhammad RIfky Ramadan 0 Reputation points

2026-03-06T09:29:42.78+00:00

Thank's for you replies, I will PM to send the detail of explanation
Raja Pothuraju 47,165 Reputation points Microsoft External Staff Moderator

2026-03-09T08:58:58.3433333+00:00

@Muhammad RIfky Ramadan, 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.

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Your answer

Raja Pothuraju 47,165 Reputation points Microsoft External Staff Moderator

2026-03-06T07:59:58.9466667+00:00

Hello @Muhammad RIfky Ramadan,

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
Muhammad RIfky Ramadan 0 Reputation points

2026-03-06T09:29:42.78+00:00

Thank's for you replies, I will PM to send the detail of explanation
Raja Pothuraju 47,165 Reputation points Microsoft External Staff Moderator

2026-03-09T08:58:58.3433333+00:00

@Muhammad RIfky Ramadan, 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.

Answer 1

Raja Pothuraju 47,165 Microsoft External Staff Moderator

Hello @Muhammad RIfky Ramadan,

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 47,165 Reputation points Microsoft External Staff Moderator

2026-03-17T09:40:58.2966667+00:00

Hello @Muhammad RIfky Ramadan,

Our engineering team had unblocked the bulk invitations on your tenant. Please check and let me know if you are facing same issue.

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Receiving "Invitations are blocked for this directory due to suspicious activity" when attempting to invite guests"

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