The article uses a comparative legal method to analyze the approaches to establishing elements of value-added tax in the Islamic Republic of Iran, the Gulf Cooperation Council states, Egypt, Indonesia, and the Russian Federation. It identifies both similarities and significant differences in the regulation of subject composition, object of taxation, tax base, tax period, rates, exemptions, and procedural aspects of administration. Special attention is given to the Iranian model, which was developed under the influence of Islamic legal tradition and years of sanctions pressure.