Is there really no way whatsoever to edit an invoice to manually add a late fee? Some sort of editing feature or late fee feature would be extremely handy. Late payments are an unfortunate fact of business life.

Yes - I also charge late fees. It would be nice to be able to add them in... I suppose I could just add them as a new slip - if I could edit an invoice.

I'm a new user, but what I'm planning to do is just add the late fee to their next invoice as a completed slip.