This discussion paper explores the role and interplay of the voluntary carbon market (VCM) and market-based cooperation under Article 6 of the Paris Agreement, focusing on how carbon credits can support the implementation of national climate targets and raise ambition beyond these targets. It covers ensuring the integrity of carbon credits, their potential authorisation under Article 6, and the high-integrity use of carbon credits and related accounting and claims, using Sweden as a case study to illustrate key issues. The study concludes that carbon credits can be a valuable tool for mobilising public and private finance for additional emission reductions and removals (mitigation outcomes), if their integrity and robust accounting are ensured, and their use complements ambitious climate action.