At the international level, States or regional integration organizations (such as the European Union) that intend to become parties to the Convention must express their consent to be bound by it. Article 43 establishes that such consent can be expressed through ratification, accession or formal confirmation. A regional integration organization is an organization constituted by sovereign States of a given region, to which its member States have transferred competence in respect of matters governed by the Convention (art. 44).
At this stage, it is important to define certain terms. For many States, expressing this consent comprises signature and ratification:
With the deposit of the act of ratification, the State establishes at the international level its consent to be bound by a treaty. Ratification, like other acts of consent, makes the international human rights norms guaranteed in the treaty legally effective vis-à-vis the State and obliges it to report to the international community on measures adopted to align its legislation, policy and practice with international standards. The significance of this differs from country to country and will be discussed below.
Some States have a one-step process to express their consent to be bound, namely accession. It consists of the deposit of an instrument of accession with the depositary and has the same legal effect as ratification; however, unlike ratification, it is not preceded by signature.
For regional integration organizations, the process is similar to the two-step process referred to above, with signature by the organization followed by formal confirmation.
States and regional integration organizations can decide to ratify and/or accede to both the Convention and its Optional Protocol or to the Convention only. Such intention needs to be reflected in the instrument executed and deposited. A precondition for signing and ratifying the Optional Protocol is having signed and ratified the Convention, although the two may occur simultaneously at the same signing ceremony.