This document discusses developing forest reference emission levels and reference levels (FRELs/FRLs) for REDD+ and their implications for economic incentives. It proposes a stepwise approach for countries to establish FRELs/FRLs based on available data and capacity. Case studies from Brazil, Indonesia, Peru and Vietnam show how to model drivers of deforestation and estimate FRELs/FRLs. Comparing FRELs to actual emissions helps determine a country's performance in REDD+ and potential payments. Establishing credible FRELs/FRLs is important for REDD+ financial incentives but must balance climate and development goals.