I'm adding a room in a basement and running a couple of new circuits. Since the electrical boxes are a trivial expense compared to everything else, I have purchased the largest capacity boxes to use for all my outlet and switch connections, rather than buying smaller capacity boxes where I have only a couple of connections to save a dime.
I have assumed it is against code to have a box that is too small, but fine to have one that is larger than required. Is this in fact the case?