Tenant-level guest invitation blocked due to suspicious activity (Need assistance from Microsoft)

馬場 智也 0 Reputation points
2026-05-18T02:13:10.57+00:00

Hello,

Our tenant's guest invitation function has been blocked due to "suspicious activity" after we attempted to invite a large number of guest users in a short period for a legitimate business project.

This is a legitimate business operation, and it is definitely not spam or unauthorized usage.

I have already contacted Microsoft 365 support, but they directed me to Azure support. However, since we do not have a paid Azure technical support plan, I am unable to open a support ticket in the Azure Portal.

Could a Microsoft moderator or engineer please support us and unlock our tenant's guest invitation capability? I am ready to provide our Tenant ID and any necessary details via a Private Message.

Thank you for your help.

Microsoft Security | Microsoft Entra | Microsoft Entra ID

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  1. AI answer

    2026-05-18T02:13:21.71+00:00

    Tenant-level blocks or lockouts such as this cannot be removed through configuration changes in the portal and must be handled directly by Microsoft support.

    For tenant-wide access or security blocks (for example, when a tenant is blocked due to inactivity or when an admin is locked out), the documented resolution path is to work with Microsoft support so that the appropriate internal teams (such as Data Protection or service engineering) can review and unblock the tenant where appropriate. This is not something that moderators or community engineers can perform from forums alone.

    Based on the available guidance for similar tenant-level issues:

    1. The tenant administrator must contact Microsoft support directly (phone or support request) and reference that the tenant’s guest invitation capability has been blocked due to suspicious activity.
    2. Support will route the case to the appropriate internal team (similar to how Data Protection is engaged for tenant lockout scenarios) to validate the tenant and unblock or adjust the protection as appropriate.
    3. While the case is in progress, do not open duplicate requests; wait for the decision and follow any verification steps requested by support.

    If the current Microsoft 365 support channel is redirecting to Azure support, the tenant administrator should call the global support phone numbers listed for Azure/Microsoft 365 support and request escalation for a tenant-level block, explaining that no paid Azure technical support plan is available but the tenant is effectively restricted by a service-side protection. For other tenant-block scenarios (such as inactivity), this is the documented and supported path to reactivation.

    Community moderators on public forums cannot directly unlock a tenant or override these protections; only Microsoft support working with internal engineering can do so after verification.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

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