Been a long while since I've been on ...
But quick question - short of simply removing (deleting) files and folders from the server, suggestions on a way to disable a website (client not paid) which could then be changed easily if they do make payment?
Change file permissions? change mapping of the domain?

In the past I've just deleted files and republished later if they do pay. But the site has been up a very long time and there's a lot on the server I'd rather not delete if not necessary to then give myself more work if I need to get it back on