AbstractMexico utilizes an emissions trading system as one of its carbon pricing instruments. Mexico’s planning, like that of other countries, includes flexible mechanisms such as offsets. Offsets allow market participants to compensate for their emissions through mitigation projects. Offsetting via participation in the Clean Development Mechanism and Joint Implementation was fundamental to the Kyoto Protocol. In contrast, the Paris Agreement is ambiguous about its use. Other national or regional offset programs, such as the EU, Australia, New Zealand, Japan, or Korea, work within emission trading systems. Subnationally, the California-Quebec program has been in effect since 2014. As Greenhouse Gases (GHGs) are global, offsetting allows market participants to compensate for their emissions through mitigation projects, whether domestically or abroad. Given their global scope, such programs present a wide variability in quality. This chapter presents an overview of offset programs worldwide and argues that non-additionality, overestimated supply, and double counting are their three most pressing quality problems. This analysis sheds light upon the nascent Mexican system and its offset program.