This research answers the request of local actors in Amsterdam who seek insights in advocacy strategies to extend the function of the municipal city card improving the position of undocumented residents in their city. This request falls into the context of a growing number of ‘solidarity cities’ facing the challenges of restrictive national immigration regimes resulting in a growing undocumented population. The need for exchange of knowledge and experience amongst cities has been highlighted by several academics. In order to provide the actors in Amsterdam with concrete recommendations, the advocacy for a city card in Zurich has been researched. On the 31st of October 2018 the municipal parliament in Zurich voted in favor of the implementation of the Zueri City Card. The Zueri City Card is a city pass that aims for legal, political, social, and cultural participation of all people living in the same city irrespective of their nationality and of their residence permit. The outcome in the parliament is a result of years of advocacy by urban actors. Guided by the Advocacy Coalition Framework, this research identifies the involved actors and their form of cooperation. It sheds light on the resources that have been used to employ various strategies. This has been done based on interviews with the key actors that were involved during this advocacy process. From this study it can be concluded the involvement of a diverse group of actors with various backgrounds, professions and expertise have served as an important foundation. Through these people, the coalition had access to deep knowledge as well as important networks. The most important contributions came from academics, a migration lawyer, the head of the SPAZ and members of the municipal parliament. The last group enabled direct access to the municipal parliament where intense lobbying campaigns took place. This research also shows how the actors have continuously adapted their strategies to the context in which they were working. They have taken into account the timing of their proposal, the sensitivity of the topic and the drastic new way of thinking they promoted.