For decades, European bureaucrats looked with disdain at the way the various states within the U.S. compute state tax.  The arm’s length principle within Europe trumped state apportionment.  Now, however, the European Commission has issued three proposal directives that deal with (i) the Common Corporate Tax Base (“C.C.T.B.”) and the Common Consolidated Corporate Tax Base (“C.C.C.T.B.”), (ii) resolution of double tax disputes, and (iii) mismatches with non-E.U. countries. To the surprise of many, the C.C.C.T.B. includes a three-factor apportionment rule for the sharing of global income by the members of a corporate group operating throughout the E.U.  Stefano Grilli of Gianni, Origoni, Grippo, Cappelli & Partners, Milan, explains proposals that have been introduced.