Advance tax ruling represents a missing link in Serbian tax law. It is aimed at advancement of taxpayers' legal certainty and deals with the tax treatment of their future transactions. By issuing a ruling at the taxpayer's request, the tax administration obliges itself to issue a tax decision with specified content in regard to the particular set of facts. Relying on comparative law method, the authors consider different types of tax rulings, conditions to be met for them to be issued, fee structures, the scope and effects of the rulings' application. While analysing the positions of administrative law scholars in Serbia on the warranty act, the authors strive to establish the legal nature of tax rulings. They point out the shortcomings of the existing system of binding tax opinions in Serbia with the aim of proposing the provisions that should be incorporated into the Tax Administration and Tax Procedure Act.