Around the world, voluntary programs are an increasingly prevalent regulatory instrument in governing nonprofit organizations. But accounts of mechanisms driving nonprofits’ participation in those programs are underdeveloped. This article combines and expands insights from voluntary regulation and institutional work theories to examine the impact of government’s informal relational work on nonprofits’ regulatory participation. Drawing on interviews and survey data from a random sample of 203 nonprofits in Shenzhen, China, the authors study the country’s pioneering government-sponsored voluntary accreditation program and its varying receptions among nonprofits. The empirical analysis shows that politically embedded nonprofits, those with closer organizational connections with the local government, are more likely to participate in accreditation. Since government agencies rely on existing regulatory networks to conduct relational work at both organizational and personal levels to persuade or cajole nonprofits to participate, they tend to direct their recruitment efforts towards more politically embedded nonprofits. However, these targeted recruitment practices may generate reactions much more complicated than the dichotomy of acceptance versus resistance, which ultimately facilitates some nonprofits seeking accreditation while deterring others.