Globalisation – and the global economic crisis – have contributed to the erosion of national tax bases and in recent years some of the biggest multinationals, among them Apple, Vodafone, Amazon, Google, Starbucks and Microsoft, have been scrutinised for their aggressive tax planning practices. Using (among other techniques) transfer pricing, inter-company lending, royalty payments for licensing agreements, cost-sharing agreements and offsetting group losses, multinational groups can achieve very low effective tax rates.