This guide provides an overview of the methods used for identifying, detecting, measuring, and quantifying (IDM&Q) methane emissions, along with references to other documents offering technical details on these methods and technologies. It highlights that the best practices for IDM&Q depend on factors such as the characteristics of the facility, the scale of emissions, the cost-effectiveness of the methods, and the specific goals of the IDM&Q program. The guide emphasizes the need for tailored approaches based on these variables to effectively address methane emissions.