The present discussion paper was commissioned by the OSCE Office for Democratic Institutions and Human Rights (ODIHR) following an official request from the President of the Committee for Auditing Democratic Quality, the Fight against Corruption and Institutional and Legal Reforms of the Congress of Deputies of Spain. The paper aims at offering Committee members a comparative overview of good practices from relevant OSCE participating States in the area of political party finance, to ultimately inform the reform efforts ongoing in Spain in this regard.