{"id":3512,"date":"2016-12-12T00:27:07","date_gmt":"2016-12-12T08:27:07","guid":{"rendered":"http:\/\/www.cloudidentity.com\/blog\/?p=3512"},"modified":"2017-01-09T01:07:08","modified_gmt":"2017-01-09T09:07:08","slug":"from-tenantid-to-domain","status":"publish","type":"post","link":"https:\/\/www.cloudidentity.com\/blog\/2016\/12\/12\/from-tenantid-to-domain\/","title":{"rendered":"From TenantID to Domain"},"content":{"rendered":"

Few years ago I wrote a post<\/a> about how you can obtain the ID of a tenant from one of its domains. Something so simple, and yet I am told that it ended up to be of use for lots of people. Yay!<\/p>\n

(BTW, at the time the root domain for Azure AD was login.windows.net<\/span>, but now it is login.microsoftonline.com<\/span>)<\/p>\n

I do often get asked how to do the inverse operation: given the tenantID, how do I determine the domain associated to it?<\/p>\n

Before we answer that question, we need to clarify things a bit. Whereas there\u2019s only one immutable, non-reassignable, gloriously opaque tenantID per tenant, every tenant can register a crazy number of domains. That said, only one of those is designated to be the default domain for the tenant. So, a better formulation would be: given the tenantID, how do I determine the default<\/em> domain associated to it?<\/p>\n

As it turns out, I don\u2019t know of a way to do that without doing an authenticated call to the Microsoft Graph API. Luckily, it\u2019s all super straightforward. Here\u2019s what we need to do:<\/p>\n