This sounds like a nice system.

Does it also tell you of its own volition if the tax office owes you money instead on a return without you having to declare anything? For example, if the tax office knows where you work as an employee and where you live, and the tax code has provisions that stipulate that an employee gains a tax advantage of 0.xx€ per kilometre commuting distance between his home and his place of work, does it factor that in or doesn't it? Because that would actually be _nice_.