The 2030 Agenda for Sustainable Development recognizes trade as an essential means of implementation for the Sustainable Development Goals (SDGs). Aid for Trade (AfT) is a mechanism which aims to support developing countries in building the capacity and infrastructure so that they can benefit from and engage in trade. AfT is an integral part of the SDG 8, in particular target 8a. on increasing AfT support for developing countries and least developed countries (LDCs). This working paper has benefited from comments shared on a previous draft by a group of various stakeholders to whom we are grateful. These insights were shared at a meeting at Quaker House in Geneva on 28 October 2021. This is a work in progress and we welcome further comments. This is the fourth paper in the series on Trade and Environmental Sustainability, which also includes papers on the topics of circular economy, environmental goods and services, and fossil fuel subsidy reform.