Since 1997, the Spanish Autonomous Communities have had the right to modify certain aspects of some of the taxes for which they have responsibility, and that traditionally had been regulated by the central state. These taxes are called "ceded" taxes. As a result, some ceded taxes are, in preactice, co-regulated by the state and the Communities. Describes the problematic reforms of the property transfer and stamp duty tax, that aimed to reallocate part of the revenues that would otherwise accrue to the state in the form of VAT, and concludes that such reallocation will almost always fail.