In the area of financial services, the creation of an internal market has, to a large extent, beenrealised through a number of harmonisation directives. Further initiatives are underway under theimpulse of the European Commission's Financial Services Action Plan.The present paper wishes to highlight some obstacles to effective market integration stemmingmainly from the way European financial law is applied in the EU Member States. The decentralisedimplementation of directives and enforcement of European law through national courts creates a riskof disparities amongst member states in the effective application of both primary and secondary EClaw. We illustrate this risk with reference to on the one hand the introduction of the Euro in theparticipating member states, and on the other hand the resistance of mainly supreme jurisdictions insome member states to submit questions of interpretation of EU financial law to the Court of Justice.Finally, the difficulties in applying EC financial law can also originate in the lack of clarity and consistency of EU law itself. The 1999 E-commerce Directive and the difficulties of applying thisdirective in the financial sector, illustrate this. We indicate some of the main difficulties associatedwith implementing this directive in the area of financial services.