Document is devoted to the methodology of surveying wages and salaries in the national economy based on administrative data sources. The primary objective of the survey on Wages and salaries in the national economy based on administrative data sources was to test the possibility of providing information on average monthly wages and salaries as well as median monthly wages and salaries in the national economy based on administrative data sources. The survey is based on data from the registers of the Social Insurance Institution (ZUS) and, additionally, on data from the registers of the Ministry of Finance and data fromthe Base of Statistical Units of Statistics Poland.