This background paper elaborates on the ongoing discussions about the up-front or ex-ante information that Parties shall provide together with their nationally determined emission reduction contributions for the post-2020 climate agreement. Due to the fact that mitigation contributions are determined nationally by each Party without any agreed types or elements, these contributions are expected to comprise a whole spectrum of diverse types of targets. For that reason, up-front information is necessary to make them transparent, comparable and quantifiable related to the progress needed to achieve the 2°C objective. Additionally, it promotes mutual understanding and trust among the Parties and it will point to the level of ambition implied by countries’ proposed targets. Explanation of equity and fairness considerations should also be addressed by up-front or ex-ante information by countries when setting their contributions.