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

Matei Doncu 0

Hello Microsoft Support,

Tenant ID: PII

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

Since Wed, Feb 18, 2026, around 1:00 PM (UTC+02:00), we have been unable to invite external users. When attempting to invite users either from the Azure portal or through our SaaS application, we receive the following error:

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

This is having a severe impact on our production operations. Our SaaS platform relies on Entra ID invitations to onboard customer users, and as a result, our clients are currently blocked from accessing the system. This affects both our EU-based and US-based customers, and today marks the fourth consecutive business day they have been impacted.

We have already opened a Microsoft support ticket and reviewed the Entra ID audit logs, but we have not identified any suspicious activity that would explain this restriction.

Please help us unblock the tenant as soon as possible

Support request id: PII

SUNOJ KUMAR YELURU 18,736 Reputation points MVP Volunteer Moderator

2026-02-23T10:14:08.5933333+00:00

Hello @Matei Doncu,

It seems that your Azure AD tenant is experiencing issues with guest invitations due to potential restrictions in the B2B collaboration settings. The error message you are encountering may indicate that invitations are blocked by cross-tenant access settings. This can happen if the settings are not configured to allow B2B collaboration with the user you are trying to invite.

You should check your cross-tenant access settings to ensure they permit such invitations. If B2B collaboration is supported but blocked, both your organization and the invited user’s organization must configure these settings appropriately.

Additionally, if you are receiving a message stating that guest invitations are not allowed for your company, it may be due to restrictions in your organization’s external collaboration settings. To resolve this, ensure that the appropriate external collaboration settings are configured correctly for your needs.

Lastly, if you’ve modified the invitation settings recently, be aware that there might be a delay of 15-60 minutes before the changes take effect.

Troubleshoot common issues with Microsoft Entra B2B collaboration

If this answers your query, do click Accept Answer and Up-Vote for the same. And, if you have any further query do let us know.
Matei Doncu 0 Reputation points

2026-02-23T12:26:19.68+00:00

Hello Sunoj,

We have not modified the invitation settings recently, nor did we have these kind of issues in the past with any user from any organization.

The receiving message is not directly related to guest invitations
VEMULA SRISAI 13,900 Reputation points Microsoft External Staff Moderator

2026-02-26T12:54:54.7266667+00:00

Matei Doncu To assist you further and forward this to Microsoft’s Data Protection Team, we need some additional information. As this involves Personally Identifiable Information (PII), please share the following details with us in private message only (do not post publicly):
Matei Doncu 0 Reputation points

2026-02-26T12:57:18.4533333+00:00

This was fixed with the help of Support Team, can be closed

Your answer

SUNOJ KUMAR YELURU 18,736 Reputation points MVP Volunteer Moderator

2026-02-23T10:14:08.5933333+00:00

Hello @Matei Doncu,

It seems that your Azure AD tenant is experiencing issues with guest invitations due to potential restrictions in the B2B collaboration settings. The error message you are encountering may indicate that invitations are blocked by cross-tenant access settings. This can happen if the settings are not configured to allow B2B collaboration with the user you are trying to invite.

You should check your cross-tenant access settings to ensure they permit such invitations. If B2B collaboration is supported but blocked, both your organization and the invited user’s organization must configure these settings appropriately.

Additionally, if you are receiving a message stating that guest invitations are not allowed for your company, it may be due to restrictions in your organization’s external collaboration settings. To resolve this, ensure that the appropriate external collaboration settings are configured correctly for your needs.

Lastly, if you’ve modified the invitation settings recently, be aware that there might be a delay of 15-60 minutes before the changes take effect.

Troubleshoot common issues with Microsoft Entra B2B collaboration

If this answers your query, do click Accept Answer and Up-Vote for the same. And, if you have any further query do let us know.
Matei Doncu 0 Reputation points

2026-02-23T12:26:19.68+00:00

Hello Sunoj,

We have not modified the invitation settings recently, nor did we have these kind of issues in the past with any user from any organization.

The receiving message is not directly related to guest invitations
VEMULA SRISAI 13,900 Reputation points Microsoft External Staff Moderator

2026-02-26T12:54:54.7266667+00:00

Matei Doncu To assist you further and forward this to Microsoft’s Data Protection Team, we need some additional information. As this involves Personally Identifiable Information (PII), please share the following details with us in private message only (do not post publicly):
Matei Doncu 0 Reputation points

2026-02-26T12:57:18.4533333+00:00

This was fixed with the help of Support Team, can be closed