Since joining the Open Government Partnership in 2011, the Indonesian Government has shown some commitment towards implementing initiatives that increase citizen voice and government and service-providers’ accountability to citizens and service users. These include a series information and communications technology (ICT)-based complaint-handling systems that give members of the public an opportunity to highlight problems with the delivery of public services to those in a position to fix them. Yet the reach and uptake of these systems – which are both national and local – varies considerably across the country, for a number of reasons. This research examines four cases of complaint-handling systems. At the national level, it reviews LAPOR!, a one-stop complaint-handling platform set up by the Indonesian Government to manage citizens’ complaints and requests via SMS, smartphone apps and a website. At the subnational level, it looks at the wider ecosystem of complaint-handling systems in three regencies: Bojonegoro, Indragiri Hulu and Indramayu. As well as evaluating how LAPOR! is used subnationally, the research looks at other systems in these regions, ranging from radio shows to regular face-to-face consultation spaces with local officials. The research asks how, and by whom, complaint-handling systems are used, identifies a series of barriers to citizens using them, and explores the factors that shape their effectiveness and impact.