Climate policies in developing countries - called nationally appropriate mitigation actions (NAMAs) in negotiation jargon - are likely to generate greenhouse gas emissions credits after 2013. To guarantee credibility of the international climate policy regime, robust measurement, reporting and verification procedures are required. Compared to concrete emission reduction projects, assessment of the additionality of NAMAs is difficult. As only a subset of policy options leads to directly quantifiable emission reductions, the challenge is to define procedures that are conservative and still provide incentives to embark on policies with long-term and indirect effects. This requires a combination of an approach using default parameters and monitoring of key factors. Experience from methodologies used under the Clean Development Mechanism should be taken into account. Analysis of a renewable energy feed-in tariff in Korea and a nationwide demand-side management programme in Thailand shows that for the former, additionality and emission impacts of policies can be assessed, but require centralized, transparent data collection systems, an effective sector organization. The latter is probably not suitable for NAMA crediting under a stringent approach. To provide incentives for a greater number of developing countries, more standardized approaches would be required to allow covering policies that are more difficult to quantify.