2021-09-202021-09-202021-09-202021-04-28https://ri.ucsal.br/handle/prefix/4638The objective of this Scientific Article is to contribute to the study and discussion related to the practical effects arising from the alteration promoted by the Code of Civil Procedure of 2015 (Law 13.105 / 2015), with regard to the extraordinary legitimacy “ad causam”, making it possible from the its duration the figure of extraordinary legitimacy of business origin. Initially, dealing with procedural legal affairs, with an explanation of the general notions, species and their requirements for validity. Subsequently, an analysis will be made about the “ad causaum” legitimacy, focusing on extraordinary legitimacy and the changes suffered due to the advent of the Civil Code of 2015. At the end, there is the Procedural Legal Business as a normative source of extraordinary legitimacy, as well as its full viability, both active and passive, taking into account the differences and practical effects, depending on the type of legitimacy that the parties intend with the conclusion of the deal.Acesso AbertoNegócio jurídico processualFonte normativaCódigo de processo civilLegitimidade extraordinária ad causamProcedural legal businessNormative sourceCivil pocedure codeExtraordinary legitimacy ad causamTrabalho de Conclusão de CursoCiências Sociais AplicadasDireito