I would have thought that the rules of when to use and when not to use checkboxes were pretty straightforward. However, after a UI review last week, it became apparent to me that this may not be the case. So when do you use checkboxes? Simply when you have a true/false, yes/no, or on/off choice:

However, checkboxes don’t work if you have a two choice option that is not a simple, binary, opposite choice. Usually you can tell if this is the case if you can’t logically put a “not” or “don’t” into the label to describe what happens when the checkbox is unchecked.

In that case, use something else like radio buttons or combo boxes:

And of course any option that requires three or more choices would be displayed similarly:

But of course, there’s always the problem of deciding when something is one option with several choices or is two or more options with dependencies:

But the simple and most common case for checkboxes still applies: only for simple binary choices!