Domain in use error, no Netlify DNS

I have been working on a new site for a friend, legionfilms-client-sites. I have an existing site of my own, hardcore-franklin-f5118b which is set up to use and It does not use Netlify DNS. When trying to add another subdomain at tomburke to legionfilms-client-sites, such as,, or, I get an error saying that the domain is already in use. I have searched the forums, but not found this situaiton - most answers say to disable netlify DNS.

hi legionfilms, just to clarify, if and www don’t use netlify DNS, are you setting up those subdomains (test, events, anything) with the DNS service that serves or are you trying to add those via netlify?

Hi Perry,

I was configuring the DNS for all domains and subdomains on my DNS provider, and then trying to add the domains to my deployment configuration in the section “Custom Domains”. I followed the usual procedure: added a cname at my dns porivder pointing to the domain for the site, and then added it as a custom domain. In this case, I got an error saying that the domain was already in use by a netlify site, though it was definitely not.

I was able to get around it by deleting from hardcore-franklin-f5118b, adding to legionfilms-client-sites, and then re-adding to hardcore-franklin-f5118b. It seems like if there is a domain added to a netlify site, you cannot add subdomains from that domain to other netlify sites. This is not what the error message says, though, and is not an obvious limitation.

Netlify doesn’t allow a a single custom domain to be used on different account. Now that this custom domain as subdomains active on a different account there will likely be errors when making changes to the custom domain or one or both accounts.

To summarize, we recommend putting all sites using any subdomain of an apex/bare/root domain all on the same account.

If there are other questions about this, please let us know.

Okay, noted, thank you. This limitation is not obvious from the documentation or the error message.

I see. I’ll bring this to our documentation team to consider. Thanks for your feedback!

Is there any possibility to change this behavior? It is quite common for different subdomains to be managed by different departments or even different companies.

We can certainly make a feature request. I doubt it will be implemented, since the reason we implemented the check is that it is more common for people to want to protect themselves from having sites configured by third parties, using their hostname which is already set up in their single account. But, it is free to ask :slight_smile:

Could you give me a bit of color to file that request? Since you control, are you really intending to delegate control of your subdomains to someone else? Or do you just have multiple logins with us and you are sharing with yourself? This will be useful information to our product team while they consider this feature for implementation, so thanks in advance for your help in understanding the use case a bit further.