Who may use the Court?
To become Parties to a contentious case before the Court, States must both have access to the Court and accept its jurisdiction: Access to the Court is granted to all States that are Parties to the Statute of the Court (Article 35(1) of the Statute of the Court). All Members of the United Nations are automatically Parties to the Statute of the Court (Article 93(1) of the UN Charter).
Subject to certain conditions, a State which is not a Member of the United Nations may become a Party to the Statute of the Court (Article 93(2) of the UN Charter). Exceptionally, the Court may also be open to States that are not Parties to the Statute of the Court (Article 35(2) of the Statute of the Court; the Security Council determined the conditions under which the Court shall be open to States that are not Parties to the Statute of the Court in its resolution 9 (1946) of 15 October 1946).
Jurisdiction of the Court is based on the consent of the States to which it is open. In a specific case, the Court has jurisdiction if the Parties have consented to the Court settling their dispute. This consent may be expressed by means of unilateral declarations (also referred to as ’optional clause’ declarations; see chapter II), in treaties (see chapter III) or through special agreements (see chapter IV). It can also be expressed after the Court has been seized (forum prorogatum; see chapter V).