E-commerce poses significant challenges for existing tax rules. One of the most important effects of e-commerce has been to de-emphasise the significance of the place where economic activity is carried out, which makes it difficult to determine which jurisdiction has the right to tax. It has also blurred the traditional distinction between the form of delivery and the substance of what is delivered. Thus, the specific tax implications of e-commerce and the threat it imposes on the established tax systems can be examined by reference to how much e-commerce tends to disrupt the concepts and principles of direct taxation and international tax treaty rules. This article explores the effect of e-commerce on the principles of direct taxation. The question is should the tax system of the future be developed at a national or an international level?