This Working Paper summarises the main findings and recommendations of the pilot study carried out in Costa Rica as part of the development of the total official support for sustainable development (TOSSD) measurement framework. The Paper includes first approximations of TOSSD flows to Costa Rica. These flows in 2016 amount to around USD 559 million of official development finance and USD 60 million of private finance mobilised through official development interventions. These first estimations were reached using OECD DAC statistics. However, these figures are likely to be largely underestimated owing to a lack of available information, particularly concerning official support to Costa Rica from the People’s Republic of China and other non-DAC providers. The pilot study also indicated that the government is able to access, collect, collate, analyse and use data on external financing to the country using national data, thanks to its institutional and IT systems. However, the legislative framework requires adjustment and there is scope for improving co‑ordination in order to avoid duplication of effort.