This report provides guidance for countries on how to estimate and report to the UNFCCC their N2O emissions from adipic acid and nitric acid production, which is the largest industrial source of N2O emissions. The report mentioned three approaches for emission factors estimation: (1) continuous monitoring at plant level, which is most accurate but can be costly; (2) periodic sampling and analysis at plant level, which is recommended by the IPCC and (3) when periodic sampling is not feasible, the IPCC provides default emission factors, which is less accurate.