The right of an action and the capacity to sue are the foundations (not the only ones) of the right to a court, and are extremely important elements of it. They enable a party or a participant in the civil procedure to act personally before the court. However, the capacity to sue is not absolute, as it can be excluded for factual or legal reasons. Therefore, the someone is not authorized to personally appear in court as a party to the proceedings. In this context, the duty of a obligatory assistance of an advocate is particularly important, i.e. the duty to appoint a professional legal representative when the law so requires. The article aims to answer the question whether, in the case of a consumer who is the weaker party to a legal relationship with an entrepreneur (arising primarily from a contract), the deprivation of the capacity to sue can be a form of their exclusion from the process, making it impossible or at least significantly hindering the enforcement of rights before a court.