We have seen a revolution in the area of communication on a worldwide scale. We begin talking about terms as globalisation, integration and deregulation of the financial market. Companies have been tax planning for decades, the questions is if Internet has made an increase of companies than uses tax planning and which roll Internet plays. It is hard to really pinpoint all the effects of the Internet because of the relatively new area of research. This thesis will take various factors under study such as globalisation, development of the offshore industry and the fight against harmful taxation by the OECD and other organisations in order to describe the effects of Internet. Another factor taken under consideration is the attitude toward using the Internet in order to evade (avoid) tax. The Internet increases secrecy in transactions, probably a cause to the sudden explosion of online transactions partly made by Internet. At the same time the tax level vary considerably from country to country and the thesis discuss the effect on high tax nations if there will be a fierce global tax competition and how countries like Sweden with the worlds highest taxes manage to maintain a high level of welfare.