Both in WTO law and in EU law there is a dichotomy between liberalization based on market access and liberalization targeting domestic regulation. Consequently, both regimes share the problem of distinguishing national measures impairing market access and those that do not have such effect, as demonstrated in the debate on the Keck principles in EU law and the US – Gambling decision in WTO law. Moreover, both the EU and the WTO exempt certain categories of 'public' services under partly comparable and complex conditions. Specific to EU law are the legal issues that have arisen because of the recent adoption of the Services Directive, which has both amended EU services law and has led to a fragmentation of the rules applicable to different service sectors in the EU. A final chapter discusses possible approaches to regulation such as home state rule, host state rule and mutual recognition from a comparative perspective.