If I start renting a second apartment in another EU country and register for residency there too, obtain their tax ID, will there be some reporting between the current and the new countries, if I don't indicate on tax return in the current country that I've moved out, and on the tax return of the new country I won't indicate that I moved there from the current country? Will I end up with two separate tax residencies that won't know about each other? The whole point of this is to obtain two tax IDs.