Nowadays, modern international law has not developed the concept of countering transnational tax crimes. To combat such crimes, it is imperative to enhance international collaboration between law enforcement agencies and financial institutions. Developing and implementing a unified system for exchanging information on financial transactions and actively pursuing violators will make the system more efficient and transparent. Efficiently utilizing modern technologies and the analytical work done by the concerned authorities will significantly enhance the efficacy of the regulation and prosecution of transnational tax offences, thereby facilitating the prompt and precise identification of the offenders. According to the results of the study, the author proposes to classify transnational tax crimes as follows: (i) tax evasion; (ii) concealment and underestimation of the volume of the taxable base of exporters; (iii) concealment of income received by foreign legal entities and their representative offices; and (iv) other types of crime. To effectively combat this phenomenon in international law, it is necessary to develop an efficient mechanism and adopt a suitable international legal document, such as a convention, agreements, standards, and regulations governing its implementation.