Unable to send B2B guest invitations from Microsoft Entra

Question

Unable to send B2B guest invitations from Microsoft Entra

Lucy Scott 20

We are currently unable to send B2B guest invitations from our Microsoft Entra tenant. All attempts to invite external users—both via the Entra Admin Portal and Microsoft Graph (/invitations)—fail immediately with the error: Portal GUI “Insufficient privileges to complete the operation.” or GraphAPI "Invitations are blocked for this directory due to suspicious activity. Please contact Microsoft support for help." No invitation email is sent and no guest user is created.

This is not a permissions or configuration issue. The action is being performed by a Global Administrator, required Graph permissions (e.g. User.Invite.All, Directory.ReadWrite.All) are granted with admin consent, and external collaboration settings are correctly configured to allow invitations. We have also confirmed that Conditional Access policies, domain restrictions, and tenant settings are not blocking the process. The issue persists across multiple admin accounts and for all external domains tested.

Given the above, this appears to be a tenant-level restriction or backend block applied by Microsoft (e.g. security, abuse, or anomaly detection). This issue is currently blocking onboarding of external users into our application. We request that you investigate whether any service-level restrictions are applied to the tenant and remove any blocks preventing B2B invitations from functioning normally.

I can provide details of our tenant and business justification for lifting the block in a DM as requested.

Many thanks

Lucy Scott 20 Reputation points

2026-03-31T14:48:44.28+00:00

The AI generated answer is exactly correct, and we have raised a ticket but a week later we are still waiting for it to be actioned despite multiple attempts to escalate via telephone and our support partner.
Lucy Scott 20 Reputation points

2026-03-31T17:33:43.72+00:00

Thank you so much it’s 2603250050002096
Thanmayi Godithi 11,905 Reputation points Microsoft External Staff Moderator

2026-04-01T14:18:25.8733333+00:00

Hi Lucy Scott ,

Thank you, We will look into the case and will keep you posted with the updates shortly.
Dominic Goldsworthy-Slatford 5 Reputation points

2026-04-21T15:39:36.3333333+00:00

@Thanmayi Godithi I really appreciate your advice earlier this month, would you happen to know the correct team or process to remove the block internally at MS for us to forward to our Support Escalation Manager/SCIM Support Engineer? Unfortunately this same issue persists with MS having spent a month bouncing round back end engineers asking for HAR traces etc with no one yet confirming they can see the tennant-level restriction. #2603250050002096
Lucy Scott 20 Reputation points

2026-04-21T15:43:46.18+00:00

Just commenting to confirm that Dominic is my colleague and is talking about the same issue and support ticket. The issue still has not been resolved.

Answer accepted by question author

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Your answer

Lucy Scott 20 Reputation points

2026-03-31T14:48:44.28+00:00

The AI generated answer is exactly correct, and we have raised a ticket but a week later we are still waiting for it to be actioned despite multiple attempts to escalate via telephone and our support partner.
Lucy Scott 20 Reputation points

2026-03-31T17:33:43.72+00:00

Thank you so much it’s 2603250050002096
Thanmayi Godithi 11,905 Reputation points Microsoft External Staff Moderator

2026-04-01T14:18:25.8733333+00:00

Hi Lucy Scott ,

Thank you, We will look into the case and will keep you posted with the updates shortly.
Dominic Goldsworthy-Slatford 5 Reputation points

2026-04-21T15:39:36.3333333+00:00

@Thanmayi Godithi I really appreciate your advice earlier this month, would you happen to know the correct team or process to remove the block internally at MS for us to forward to our Support Escalation Manager/SCIM Support Engineer? Unfortunately this same issue persists with MS having spent a month bouncing round back end engineers asking for HAR traces etc with no one yet confirming they can see the tennant-level restriction. #2603250050002096
Lucy Scott 20 Reputation points

2026-04-21T15:43:46.18+00:00

Just commenting to confirm that Dominic is my colleague and is talking about the same issue and support ticket. The issue still has not been resolved.

Answer 1

Thanmayi Godithi 11,905 Microsoft External Staff Moderator

Hi Lucy Scott,

The behavior described matches a tenant-level restriction that cannot be resolved through local configuration, roles, or Graph permissions. The error message from Microsoft Graph explicitly states that invitations are blocked for the directory due to suspicious activity and instructs to contact Microsoft support. There is no configuration change in Microsoft Entra ID that will clear this condition from the admin side.

We need to send the details asked via Private chat to Data Protection team to resolve the issue from backend.

If the resolution was helpful, kindly take a moment to click on and click on Yes for was this answer helpful. And, if you have any further query do let us know.

Thanmayi Godithi 11,905 Reputation points Microsoft External Staff Moderator

2026-04-03T10:58:22.4566667+00:00

Hi Lucy Scott ,

If the resolution was helpful, kindly take a moment to click on and click on Yes for was this answer helpful. And, if you have any further query do let us know.