The most common reason is simply that DNS hasn't finished propagating - nameserver changes can take up to 24-48 hours. If it's been longer, check these:
- Both nameservers are correct. Re-check them against your welcome email or client area for typos.
- The change actually saved at your registrar - some panels require a separate confirmation.
- The domain isn't expired. An expired domain stops resolving regardless of nameservers.
- The site exists on the server. The domain should be added in cPanel and files uploaded to its document root.
Clear your browser cache or test on mobile data, since your local network may still cache the old DNS. If everything looks right after 48 hours, open a ticket with your domain name and we'll trace where the lookup is failing.