Factoring is one of the most developed and useful agreements in international trade in recent decades, to such an extent that it talks about an international factoring agreements, characterized in any case by the disparity of internal regimes, a problem which does not necessarily arise from the lack of general theory, or from the adhesion of countries to a single contractual framework, but from the need for factories and factories in their international trade relations to incorporate rules governing their contractual relations . The elements of validity, effectiveness, legal requirements, classes of factoring, its general theory, and the peculiarities in the Colombian system, will be the basic notes that will treat this paper. Likewise, special reference will be made to the assignment in international legal traffic through the study of texts, such as the United Nations Convention on the Transfer of Credits, the Unidroit Principles on International Commercial Contracts, and the Unidroit Ottawa Convention on International Factoring of 1988.