Global warming issues are a widespread problem around the world and the emissions of greenhouse gases is one of the main contributors. The transport sector emits a significant amount of greenhouse gas emissions; thus, this contributes to global warming. To tackle this challenge the Swedish state introduced in July 2018 a system called bonus-malus system which aims to increase the proportion of eco-friendly cars and in the long run reducing greenhouse gases emissions from the transport sector. This paper examines the tax system within the Bonus-Malus system. Primarily investigating if Malus, tax system, impacted the demand for electric vehicles since it introduced. The study conducted based on a short panel data from Sweden´s 21 counties for the period 2016-2020 and the analysis method applied is a regression analysis. The results of this thesis confirm a strong positive relationship between the share of newly registered battery electric vehicles (BEV) and the Malus, but much weaker influence of the other studied variables. Suggesting that tax system induce on emission seem to be efficient at boost the demand for BEV