Facilitating the transition to a climate-friendly and resilient economy requires huge investments. The EU has committed to spending 20 % of its 2014-2020 financial resources on climate-related measures. Against the backdrop of the Paris Agreement and of the Sustainable Development Goals set by the United Nations, such a high-level political objective acquires new salience in the negotiations for the post-2020 EU budget. The European Commission has proposed to raise this objective to 25 % of the EU budget in the next programming period, while the European Parliament has called for an even more ambitious approach. Tracking and reporting climate-related expenditure pose several challenges. This analysis describes how climate action has been mainstreamed in the EU budget so far, as well as possible developments for the 2021 2027 period. The EU appears on track to almost reach its 20 % objective by 2020. Assessments of the tracking methodology and of its impact have identified both achievements and shortcomings. The creation of a broad political objective is deemed to act as a driver of increased focus on climate considerations across different policies. Recommendations for improvements include the development of a stronger performance framework.