Show All Headings in Word Contents Page

I was using a contents page in one of my Word documents and it was only showing heading items 1 to 3 and not the 4 and 5 levels. It transpires that by default Word only shows heading levels 1 to 3, but it is quite easy to change!

Click on your contents table and then press Alt+F9. This changes the view to look something like this:

Where it shows "1-3", change it to whatever heading level you want it to show. So if you want it to show up to level 5, change it to "1-5". Press Alt+F9 again and it will switch back to the view you are more accustomed to. You may need to do an Update Table... to show the new levels.

I've since found a useful site that has some more info on customising the table of contents and more specifically it's switches.