Developers do not give invoices should go to the tax bureau to complain, if this time your developer does not give you invoices, then you can give the tax bureau to complain, as long as you complain after the tax bureau to deal with, so this time the tax bureau will look for units of the staff for an interview, and then let them to give you timely invoices, or else they will be The first thing you need to do is to get your hands dirty.