The proliferation of more than 50 green taxonomies has shown the increasing interest of policymakers worldwide to foster green capital flows and counteract greenwashing. The Sustainable Finance Taxonomy Mapper (SFTM) aims to foster interoperability across taxonomies worldwide through mapping taxonomy design features as well as technical screening criteria across economic activities substantially contributing to climate or wider environmental objectives. The paper lays out the methodology adopted in the SFTM to map an initial set of 11 taxonomies.