Map a custom domain to a WordPress Multisite subsite when that site should have its own public address while remaining part of the network. Current WordPress supports native domain mapping, but DNS, hosting routing and HTTPS must also recognise the custom domain.
IN THIS ARTICLE
01 Prepare the domain
Confirm ownership and the intended subsite. Record the current address and take a network backup. Ask us to confirm the supported way to attach the additional hostname to your hosting service so it routes to the network's installation. Do not create a separate WordPress installation at that hostname accidentally.
02 Configure the mapping
- Set the custom domain's website DNS records to the intended hosting destination while preserving any separate mail records.
- Configure the hostname in the hosting account and arrange a valid HTTPS certificate for it.
- Verify that the hostname reaches the correct network installation.
- As a Super Admin, open Network Admin > Sites, edit the intended subsite and set its Site Address to the complete new HTTPS URL.
- Save and test both public pages and administration access on the mapped domain.
Do I need an old domain-mapping plugin?
Native mapping is available in modern WordPress. An existing network may still have a legacy mapping integration that needs a planned migration, but a new mapping should not automatically copy an obsolete plugin recipe. Check the network's actual architecture before removing any legacy component.
Why does login fail after mapping?
Check certificate validity, redirects, the saved site address and cookie-related configuration. Clear the relevant browser cookies after verifying the configuration. Do not add arbitrary host-header-based constants or broad cookie settings without understanding the network's trusted hostnames. Preserve access through the network administration URL while investigating.
03 Check content and routing
Review stored media links, canonical URLs and any plugin settings that refer to the old subsite address. Add an appropriate redirect from the previous public address where required, and test for loops. Mapping a domain does not automatically transfer its registration or email service.
04 Record the operational dependency
Include the domain, certificate renewal and DNS ownership in the network inventory. Verify forms, sign-in flows and external callbacks that may validate the hostname. If the domain must later move to a standalone installation, plan that as a separate data migration rather than merely removing the mapping.