With a growing number of citizens living abroad, incentives and strategies to reach diasporas have become increasingly important for political actors. National political parties respond to new competitive transnational environments and engage with citizens living outside their country of origin. Such engagement offers channels for political communication, democratic representation and mobilisation of external voters. However, compared to traditional national party organisations with regional branches and local sections, we know little about the “party abroad” as an organizational unit because it is a relatively new concept that uses a different set of transnational instruments. In this study, I aim to map and classify the official transnational infrastructure of all parliamentary parties in Switzerland, Germany and Austria. By examining official party documents, I compare organisational varieties and develop an analytical framework to measure the scope and degree of transnational party infrastructure.