The code below will completely disable any commenting and trackback features in WordPress. It is in response to the usual issue whereby you think comments have been completely turned-off only to get a notification that there are a new comments waiting moderation.

This code won’t turn off any “This post has X comments” or front-end code that displays comments that may be in your theme. Instead it removes the ability for comments to be added/stored against posts. To remove front-end comment boxes and listings you’ll need to change your individual templates

Simply copy and paste into your functions.php file in your WordPress theme folder.