This dissertation consists of three empirical studies contributing to the literature on tax planning and transfer pricing.The first study investigates the impact of U.S. state taxation on the geographical allocation of the intra-U.S. trademark ownership of large U.S. multinationals. The study documents that the U.S. State of Delaware has a leading position as a trademark holding location and that the major-ity of trademarks are registered there. Moreover, it contains an analysis of the effectiveness of group consolidation (combined reporting) and provides evidence that combined reporting signifi-cantly reduces the share of trademarks allocated to Delaware. Nevertheless, the identified effects indicate that Delaware-based trademark strategies have not been entirely abandoned. The second study examines the use of information technologies in a firm’s transfer pricing system. In particular, it investigates the role of firms’ information environment in mitigating the conflict of managerial and tax objectives in transfer pricing. The study provides empirical evi-dence that if firms facing conflicting objectives make intensive use of information technologies, they are more profitable, report lower effective tax rates, and face lower tax risk.The third study analyzes whether the strictness of transfer pricing regulations and their en-forcement affect intrafirm trade of U.S. multinational firms. In particular, the results suggest that stricter transfer pricing in a country decrease the tax rate sensitivity of bilateral U.S. intrafirm trade. Thus, the possibilities of U.S. multinationals to engage in transfer pricing related tax plan-ning schemes are effectively reduced.