This guide is designed to steer makerspaces across the Baltic Sea Region on a transformative journey towards circularity, aligning with regional ambitions for sustainability and economic resilience. It is a practical and helpful tool to effectively transition to a circular economy, ensuring that their contributions to sustainability are impactful, measurable, and aligned with the Baltic Sea Region goals. The guide elaborates on ten aspects or must-haves for makerspaces to transition into circular makerspaces. Each must-have includes a checklist of the aspect-specific actions. The checklist is followed by a list of tools and templates that makerspace can use for their convenience.