Before the committee can proceed to consider a complaint on its merits or substance, it must verify that the complaint meets the formal requirements of admissibility. When considering the issue of admissibility, he may take into account one or more of the following factors:
If the applicant is acting on behalf of another person, does he/she have the necessary permission or does he/she have other grounds for such actions?
Is the applicant (or the person on whose behalf the complaint is submitted) a victim of the alleged violation? It must be proved that the alleged victim is personally and directly affected by the legislation, policies, practices, actions or omissions of the State party against which the complaint is directed. It is not enough to challenge legislation or public policy or practice in the abstract (the so-called actio popularis) without demonstrating how it personally affects the alleged victim.
Is the complaint compatible with the provisions of the treaty referred to? The alleged violation must relate to the right that is actually covered by the protection of this agreement. For example, a complaint submitted under the Optional Protocol to the International Covenant on Civil and Political Rights cannot relate to a violation of property rights, since this Covenant does not protect this right. In this case, the claim will be, in legal terms, unacceptable ratione materiae.
Should the relevant committee re-examine the facts and evidence in a case that has already been examined by the national courts? The Committees are competent to consider possible violations of the rights guaranteed by the relevant treaties, but not to act as an appellate instance in relation to national courts and tribunals. They cannot, in principle, consider decisions concerning the administrative, civil or criminal liability of individuals, nor can they consider the question of innocence or guilt.
Is the complaint sufficiently substantiated? If the relevant committee, in the light of the information provided to it, considers that the applicant has not sufficiently presented/presented the facts and arguments, it may dismiss the relevant case as insufficiently substantiated and, therefore, inadmissible.
Does the complaint relate to events that took place after the entry into force of the complaints mechanism for the State party concerned? As a rule, the committee does not consider complaints if the relevant facts occurred before that date, since the complaint will be considered inadmissible ratione temporis. However, there are exceptions to this rule, for example, when the consequences of the event in question lead to a continuing violation of the provisions of the treaty.
Has the same issue been submitted to another international body for consideration? If it has been submitted to another treaty body or regional mechanism, such as the Inter-American Commission on Human Rights, the Inter-American Court of Human Rights, the European Court of Human Rights, the African Commission on Human and Peoples' Rights or the African Court of Human and Peoples' Rights, the committees cannot consider the relevant complaint. This rule aims to prevent unnecessary duplication at the international level. If the issue has been submitted to another body for consideration, the applicant must indicate this in the initial complaint, specifying the body to which the relevant issue was referred.
Have all domestic remedies been exhausted? As indicated above, the cardinal principle determining the admissibility of a complaint is that the applicant must first exhaust all relevant remedies available in the State party before submitting a complaint to the committee. This usually includes defending the complaint in the national justice system, except in cases where there is sufficient evidence that the proceedings at the national level were unreasonably prolonged or if they would have been obviously ineffective. The applicant must explain in detail the reasons why he believes that this general rule should not be applied. The Committees consider that doubts alone about the effectiveness of a remedy do not exempt applicants from the obligation to exhaust it. In addition, if the State party concerned considers that domestic remedies have not been exhausted, it should provide detailed information on effective remedies available.
Does the reservation made by the State in relation to the relevant treaty prevent the consideration of the complaint? Reservations are formal declarations by which States can limit the obligations they undertake in accordance with a specific provision of a treaty. A State could have entered a reservation on the substance of the treaty or a procedural reservation on the complaints mechanism limiting the competence of the committee to consider certain communications.
Is the complaint an abuse of procedure? In some cases, committees may conclude that a claim is frivolous, litigious, or represents an improper use of the complaints procedure and dismiss it as unacceptable, for example, if the same person repeatedly submits complaints to the committee on the same issue, despite the fact that they have already been rejected.