One of the most important characteristics of the Commission is that it may conduct an investigation only with the consent of the parties involved. A State does not automatically recognize the Commission's competence by signing or ratifying Protocol I, but only by separately affirming that recognition. A State may make a comprehensive declaration, thereby permanently recognizing the Commission's competence, or it may consent to the investigation of a particular dispute.
A comprehensive declaration can be made when signing, ratifying, or acceding to Protocol I, or at any subsequent time.
By making such a declaration, a State authorizes the Commission to enquire into any conflict that may arise between itself and another State that has made the same declaration. No additional approval is then required for the Commission to act. It goes without saying that by accepting the Commission's competence, a State obtains the right to request an enquiry regarding conflicts between States that have likewise accepted that competence, regardless of whether it is itself involved in the conflict.
While there is no standard form, the State must unambiguously announce that it recognizes the competence of the International Fact-Finding Commission as set out in Article 90 of Additional Protocol I to the Geneva Conventions of 1949. The declaration must be submitted to the depository, i.e. the Swiss Confederation.
Both the Swiss government and the ICRC Advisory Service on International Humanitarian Law have drafted model declarations of recognition, which States are free to make use of.
A party to an armed conflict that has not made a comprehensive declaration may accept the Commission's competence on a temporary basis, that acceptance being limited to the specific conflict in which it is involved. This form of recognition does not constitute permanent acceptance of the Commission's competence.
Any party to a conflict may ask the Commission to conduct an enquiry. If a party which has not given its consent is the object of a complaint, the Commission will convey the allegation to that party and ask it to consent to an enquiry. If consent is refused, the Commission is not authorized to conduct an enquiry. If consent is granted, the enquiry procedure will begin.
In a conflict involving parties that have not made the comprehensive declaration, a warring party will not be bound by a previous consent: it is up to that State to decide whether to reaffirm the Commission's competence should it become the object of a complaint. Obviously, the request for an enquiry must come from a State that has also recognized the Commission's authority.