Deleting is quick and there is no undo. The order below takes ten minutes and keeps everything that turns out to matter later - and something always does.

Take a copy first, of more than the files

  • Files and database, obviously.
  • Mail. Deleting hosting deletes the mailboxes, and the messages with them.
  • The DNS zone. Export it. Rebuilding thirty records from memory is a bad afternoon.
  • The certificate and any keys, if anything else depends on them.

Then check what points at it

A site being removed is often referenced by something that is staying: a form that posts to it, an image hot-linked from another site, a cron job on a different server, an API a mobile app still calls. Search for the domain before it stops answering.
grep -rn "old-site.com" /var/www/ --include="*.php" | head -20

Leave a redirect, not a hole

If the content moved, redirect it. A 301 keeps the standing the old address earned and takes visitors to the right place; deleting it drops both.

server {
    server_name old-site.com;
    return 301 https://new-site.com;
}

And if it is genuinely gone

Return 410 rather than 404. It says "this existed and is deliberately gone", and search engines drop it faster and more cleanly than a 404 that might just be a mistake.

The order

  1. Copy everything, including mail and DNS
  2. Verify the copy opens — Not that it exists - that it opens.
  3. Put the redirect or the 410 in place
  4. Wait a fortnight — Watch the log for anything still asking.
  5. Then delete
Do not cancel the domain at the same time. Keeping the name for another year costs little and keeps the redirect working, which is the part visitors actually meet.