YEAR 2023 No 1

ISSN 2182-9845

The concurrent non-performance and the Portuguese Jurisprudence

Tomás Selas


Bilateral breach of contract; Contributory fault; Exceptions of non performance; Synallagma; tu quoque.


The Civil Code is designed to solve cases where one single party doesn’t perform their contractual obligations. The present article aims to be a contribute for the study of breach of contract by two parties, a term used to describe when both parties of a contract fail to perform its contractual obligations, starting from the analysis of the case solved by our Supreme Court of Justice in 14-01-2021, proc. n.º 2209/14.0TBBRG.G3.S1  related to a construction/building contract. It discusses if it is possible that the failure of one party can be relevant when the other party was already in a breach of contract.  Because our strict law isn’t specific enough to solve these problems, we need to consider other principles of justice intended to compose the solutions already established by our Code, that were built to solve the traditional breach of contract.