Background: According to international law, a state responsible for internationally wrongful acts is obliged to fully compensate for the damage caused by such acts (Responsibility of States for Internationally Wrongful Acts, Art. 31). Accordingly, victims who suffered losses as a result of such actions are entitled to compensation. To implement these fundamental principles, the Committee of Ministers of the Council of Europe established the Register of Damages Caused by the Aggression of the Russian Federation against Ukraine. It is just the first of three elements of the future compensation mechanism for Ukraine (the other two, yet to be created, are the compensation commission and the compensation fund). However, to get compensation, every victim of the war will have to prove his or her case before the future commission. In this regard, the evidentiary standards will become critical. To understand how future compensation mechanism for Ukraine could operate, it is useful to study the practice of similar institutions. The UN Compensation Commission deserves special attention, as it could provide valuable insights into how war-related damage must be proven to warrant compensation. Methods: The article’s primary purpose is to explore the approach adopted by the UN Compensation Commission with respect to evidentiary standards. To this end, the article will first outline the general framework of the Commission's work, its purpose and organisational structure. It is then necessary to describe the categories of claims reviewed by the Commission, since - as will be shown later - the Commission applied a diversified approach: different categories of claims were subject to different evidentiary standards with varying degrees of exactingness. This differentiation was necessitated by the prioritisation of claims and the use of an expedited procedure for reviewing first-priority claims. This main part of the study will focus on the Commission's documents that illustrate its approach to evidentiary standards. First, the three evidentiary standards applied by the Commission will be outlined and explained: proving the incident alone with no need to establish the extent of the damage; proving damage on the basis of a "reasonable minimum" of evidence appropriate in the circumstances; and proving damage on the basis of documentary and other evidence sufficient to establish the extent of the damage. The article will then analyse how these three standards were applied in practice to the selected categories of personal injury claims. Finally, the conclusions will consider what takeaways can be drawn from the Commission's case law for the Ukrainian case. Results and Conclusions: In times of armed conflict and occupation, gathering evidence of harm is notably challenging for victims due to various reasons. This fact calls for special consideration from international compensation mechanisms, which cannot adhere to the rigid formalities used in regular court proceedings. That is why the international law of evidence is adaptable and seeks to adjust to claimants' unique situations. This adaptability is exemplified by the relaxed and diversified standards of proof utilised by the UN Compensation Commission. Diversifying the standards of proof in the practice of the UN Compensation Commission consisted of applying three different approaches to different categories of claims. In addition, the burden placed on claimants was eased by presumptions developed in the Commission's case law. The pioneering approaches of the UN Compensation Commission should be applied and refined within an international compensation mechanism for Ukraine. This entails prioritising individual claims, introducing both regular and expedited tracks for processing claims, and ensuring flexibility with regard to the burden of proof and evidentiary standards to accommodate the challenges of wartime evidence collection without overwhelming victims.