The study is comprised of four parts. First, a theoretical concept of formulary apportionment is presented in order to define the role that formulary apportionment could take in the area of profit allocation within the Internal Market. This is followed by an in-depth evaluation of the practical experiences of four jurisdictions (United States, Canada, Switzerland and Germany) with formulary apportionment at the subnational level. Next, a comprehensive proposal for harmonization on the basis of consolidation and apportionment is developed, using the insights from the foregoing theoretical considerations and comparative analysis.rn rnThe book concludes with an overall analysis of the merits and drawbacks of the proposed model for harmonization which suggests that consolidation and formulary apportionment could indeed represent a workable solution to numerous problems of corporate taxation within the Internal Market.