Greenhouse gas (GHG) emissions from shipping contribute meaningfully to climate change. Despite significant efforts of the International Maritime Organization over recent decades, existing measures are still inadequate for achieving net-zero GHG emissions in the shipping sector and multilateral negotiations hold little promise for improvement. This article considers the polluter pays principle (PPP) as an alternative or additional pathway for tackling marine GHG emissions. The article focuses on the challenges in identifying polluters, which is the key issue that must be addressed before the PPP can be applied. Specifically, the article presents an analytical framework and examines various approaches to identifying marine GHG emissions polluters. Firstly, it identifies the polluter from a general perspective, using three approaches: examining the issue broadly, reviewing international conventions and European Union initiatives that incorporate the PPP, and analyzing selected domestic legislation reflecting the PPP. The article then focuses on maritime shipping, considering specifically two types of contract of affreightment – charterparties and bills of lading – while highlighting key factors in identifying the polluter. In conclusion, the assessment of causal links, along with operational and management decisions regarding the vessel, attribute the status of primary polluter to the shipowner, demise charterer, and time charterer.