This study catalogues party finance laws in multiple countries and identifies institutional factors that correspond to laws countries choose to adopt. Using data from international sources, we assessed differences in the regulation of money in elections in over 120 states. We classified countries into four types of party finance regimes along two axes: one that reflects regulations affecting party income and a second that reflects rules intended to make party finance more transparent. We found that two institutional factors are associated with the extent of government regulation in financing politics: the type of legal system and the use of proportional representation. Our study provides a new conceptual framework to categorize party finance regimes based on various types of regulations and the linkages between institutional factors and the extent of regulation. This conceptual typology offers a method to assess relationships between finance systems and political outcomes.