Why is my tenant suddenly not allowing me to invite guest users?

Question

Why is my tenant suddenly not allowing me to invite guest users?

Paul Stirpe 1

We have setup a new tenant and successfully invited some guest users. Suddenly, whenever I invite a guest user ("Invite external user"), I receive a vague error in the alert pop-up indicating " User invitation failed, Insufficient privileges to complete the operation." I am the global tenant admin of the tenant and have also successfully previously invited guest users without issue. What could be the issue? Thanks.

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3 answers

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Answer 1

Paul Stirpe 1

I believe I have found the issue. It seems upon new tenant creation, if one invites more than 9 guests to the tenant, the tenant disables ones ability to add more guests and throws this same error. I just created a new tenant, invited guest external users, and on adding the 10th one, it throws this same error. Can Microsoft please look into this and disable this new blocker that Microsoft seems to have been up in place.

Nathan Roberts (SN) 13,031 Reputation points Student Ambassador Volunteer Moderator

2026-08-02T09:55:16.94+00:00
Hey there, Paul Stirpe

I have just tried with mine, and could invite more then 9. I had around 10 users (all created by me in a different tenant and invited to mine).

From what I can find, Microsoft doesn't have a policy that actually sets a limit on how many guests can be invited to a tenant. However, what find may suggest that this depends on how long the tenant has been active for.

It could be that newly created tenants can not invite more then 9 users because they have only just been created, thus not trusted. However, I couldn't find information to back this up, other then what you have stated with your newly created tenant.

However, with this being said, it does leave a few questions I have which are:

Has your main tenant got a verified domain attached to it?

How long have you had your main tenant for?

Thanks,
Nathan
Paul Stirpe 1 Reputation point

2026-08-03T00:55:56.7533333+00:00

Hello Nathan, I have reproduced this with another tenant that I just created. It also exhibits the exact same behavior. So, it is reproducible in 2 new tenants. After the 9th guest, I am blocked with the same message.

Answer 2

Nathan Roberts (SN) 13,031 Student Ambassador Volunteer Moderator

Hey there, Paul Stirpe

It could be that the ability to invite guest users to the tenant has been changed so that no one in the tenant can invite guest users. Please can you sign into your account here: https://entra.microsoft.com/#view/Microsoft_AAD_IAM/CompanyRelationshipsMenuBlade/~/Settings/menuId/ExternalIdentitiesGettingStarted

Please can you navigate to guest invite settings.

User's image

Please can you make sure that the option "Member users and users assigned specific admin roles can invite guest users including guests with member permissions" or "Only users assigned to specific admin roles can invite guest users"

Hope this helps,
Nathan

Paul Stirpe 1 Reputation point

2026-07-29T16:19:56.8366667+00:00

Nathan, still same issue after setting "Only users assigned to specific admin roles can invite guest users".
Nathan Roberts (SN) 13,031 Reputation points Student Ambassador Volunteer Moderator

2026-07-29T16:57:58.4733333+00:00

Hey there, Paul Stirpe

Please can you go to the External Identities, cross tenant access settings here: https://entra.microsoft.com/#view/Microsoft_AAD_IAM/CompanyRelationshipsMenuBlade/~/CrossTenantAccessSettings/menuId/ExternalIdentitiesGettingStarted

Please can you check that the collaboration settings for B2B are set to allowed

Are these set to allowed?

Thanks,
Nathan

Answer 3

Nathan Roberts (SN) 13,031 Student Ambassador Volunteer Moderator

Hey there, Paul Stirpe

User invitation failed, Insufficient privileges to complete the operation.

Please can you sign into your account on the users page on the Microsoft Entra ID portal here: https://entra.microsoft.com/#view/Microsoft_AAD_UsersAndTenants/UserManagementMenuBlade/~/AllUsers/menuId/

Please click onto your user account, then click onto "Assigned roles" from the left-hand side navigation menu.

User's image

Please search for a role called "Guest inviter"

User's image

If you can not find this role, please click onto "Add assignments" and add this role to your account. This will allow you to add/invite guest users to your tenant.

Hope this helps,
Nathan

Paul Stirpe 1 Reputation point

2026-07-29T15:11:06.4466667+00:00

Hello Nathan, Thank you for the response. I did as you suggested and am getting the same exact error - not able to successfully invite guest users.
Paul Stirpe 1 Reputation point

2026-07-29T15:11:37.48+00:00

Hello Nathan, Thank you for the response. I did as you suggested and am getting the same exact error - not able to successfully invite guest users.
Paul Stirpe 1 Reputation point

2026-07-29T15:12:05.5033333+00:00

Hello Nathan, Thank you for the response. I did as you suggested and am getting the same exact error - not able to successfully invite guest users.