KB - Reset cross-tenant access policies back to the system default.

This is a knowledgebase item. Hope it helps you out someday.

The issue#

Changes have been made to the default settings in the Azure AD cross-tenant policies. You want to revert them, but there is no button in the Azure portal UI to do that (at the moment of writing this article)

Solution#

This can be done using the Graph API. The easiest way is using Graph Explorer. So, how does that work?

Browse to https://aka.ms/ge, and make sure that you are signed in. First, check if you have consented to the Policy.ReadWrite.CrossTenantAccess permissions.

Then, use this API request:

POST https://graph.microsoft.com/beta/policies/crossTenantAccessPolicy/default/resetToSystemDefault

If successful, this action returns a 204 No Content response code. {}

The default settings are now restored:

Inbound access settings

Outbound access settings

More info: crossTenantAccessPolicyConfigurationDefault: resetToSystemDefault - Microsoft Graph beta | Microsoft Docs

Stay safe!