This discussion paper explores key issues and options to ensure robust accounting of international transfers from market mechanisms under Article 6 of the Paris Agreement. The paper first provides an overview of key issues that must be addressed to ensure robust account and highlights approaches to address them. The further analysis focuses on: the nature and scope of „internationally transferred mitigation outcomes“ under Article 6.2 of the Paris Agreement, discussing possible definitions and scopes; how double counting of emission reductions could be avoided through „corresponding adjustments“, taking into account the diversity of nationally determined contributions under the Paris Agreement; how the vintage of mitigation outcomes and the timing frames of mitigation targets, including single-year targets, can be accounted for; and how the transfer of mitigation outcomes can be tracked.