A proposal to use UN assessed contributions as a means of providing sustainable and predictable financing for African Union (AU) peace support operations is perhaps the most contentious issue facing the two institutions. The Security Council’s attempts to agree on a resolution that would see a 25:75 funding split between the AU and UN for Council-authorised AU-led missions ended acrimoniously, threatening to taint relations with its AU counterpart, the Peace and Security Council (PSC). Central to the dispute are doubts about the AU’s ability to pay its share. Discussions are on hold until African leaders meet in February 2020 to decide if and how the AU will meet its obligation. The timeout presents a much needed opportunity for the AU to clarify key positions. UN member states need to do the same. They should then come back together and make the necessary compromises to get the proposal off the ground – an outcome that would serve both institutions and their common goals of conflict prevention, mitigation and resolution in Africa. This report sets out recent developments in the debate on the use of UN assessed contributions to finance AU peace operations, examining ill-tempered negotiations at the Security Council and PSC in 2018 and 2019 that have led to an impasse. It analyses the principal barriers to agreement and suggests next steps as the parties seek to break the deadlock.