> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/cortex-xpanse/inventory/manage-business-units/business-unit-management-for-domains-and-subdomains.md).

# Business Unit Management for Domains and Subdomains

Any user-specified change to the business unit (BU) for a domain or subdomain is called an *override*.

When you modify the BU for a domain, typically you have the option to change the BU for the domain only or for the domain and all related subdomains. There are two situations where you will not be able to update all or some of the related subdomains:

* If a subdomain has a BU override that makes it different from the BU for the parent domain, then you cannot change the subdomain by selecting **Make changes to related subdomains**. In this case, before you confirm the BU updates you will see a dialog box indicating that all or some of the subdomains have already been reassigned to different BUs.

  If a domain and subdomains have the same BU assignment, you will be able to update the BU for the subdomains by selecting **Make changes to related subdomains**. And you can always update the BU for an individual domain or subdomain, regardless of whether it has been reassigned before.
* If you don't have the right access permissions in Expander to view or modify subdomains, you will not be able to update the BU assignment. In this case, you will see a message in the dialog indicating that you do not have permission to update the subdomains. Click **Proceed Anyway** to update the BU for the domain only.


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