Double taxation conventions (or conventions) are bilateral agreements between two countries that grant income tax duties between these countries and thus prevent double taxation of income. Preventing or eliminating double taxation is an important aspect of countries` investment climate, which is essential for investment flows, the exchange of goods and services, the movement of capital and people, and the transfer of technology. (1) an updated version of Article 1, with a single tax-transparent clause, and a savings clause specifying that the taxation of residences is generally maintained by tax treaties; (2) a new article 12 bis relating to the taxation at source of royalties for technical services without the need for permanent establishment; 3. A new section 29, which contains provisions relating to the right to contractual benefits; and (4) a series of new versions of several articles aimed at curbing the erosion of the tax base, evasion and evasion, which highlight these important elements of the purpose and purpose of tax treaties. The growth of investment flows between countries depends largely on the prevailing investment climate. The prevention or elimination of international double taxation on equal income contributes significantly to such a climate. The UN Convention on Double Taxation between Developed and Developing Countries (the UN model) promotes the prevention of double taxation, but in such a way that, compared to other types of contracts, more tax duties are maintained under a tax treaty compared to those of the investor`s „country of residence“. This is an approach that developing countries have found particularly useful in their desire to reconcile a healthy investment climate with the need to finance development through the mobilization of national resources. The main objectives of this revision of the UN model were to take into account changes in international tax policy, which are generally relevant to countries. The main changes to the new version compared to the previous one are the most important: this book aims to strengthen the capacity of national tax authorities and finance ministries in developing countries to effectively identify and assess their needs for negotiation and management of tax treaties.