If you’re using SharePoint Online and you’re trying to use the Content Type Hub you have probably come across the same problem. At some point you’ll realize that you can’t create a Content Type Hub because one has already been provisioned for you by Microsoft.
For those of you that are not aware your Content Type Hub is available at:
Great, so now you try to access the site collection but you quickly realize that you don’t have access. Boom. Access Denied.
The only user that has access to this auto-generated site collection by default is the account that originally provisioned Office 365. This normally wouldn’t be a problem if you could go to your SharePoint admin center and modify the site collection administrators. However, the Content Type Hub is a hidden site collection… so now you’re stuck. It really isn’t the best situation to have to go hunt down the original user so I started poking around to find an alternative.
It turns out that there is a page called TA_SiteCollectionOwnersDialog.aspx that handles the management of Site Collection Administrators. And this page takes a single simple parameter called “site”. So if you want to access your Content Type Hub without contacting your original administrator (and you’re a Global Administrator within Office 365) just go to the following URL.