In this paper, we examine some of the most important aspects that may affect a company's sales and use tax liability. In particular, we focus on exemptions, research and development, transfers, and trade shows. Along with exemptions, we cover the tracking of exempt certificates and why it is critical to provide proof of the exemption. Then, we look at the sales tax nexus to review where taxes may be due and how the Supreme Court’s Wayfair decision has affected sales tax nexus, and how that can affect your obligations. The paper concludes with steps you can take to reduce your overall sales and use tax risk and liability.