Floods can have a significant impact on the economy, making it crucial for governments to implement policies that improve risk management and reduce the impact of such events. However, previous failures in policy implementation in developing countries with megacities prone to floods have been linked to a lack of trust among urban populations in their governments. This lack of trust is believed to affect private flood preparedness in response to flood events. Our study investigates the relationship between trust in the government and household preparedness for floods in Jakarta, Indonesia. In 2018, we conducted a unique household survey, and our results indicate that households that trust the government’s ability to manage floods and flood insurance are more likely to have flood preparedness measures in place, such as physical mitigation, planned physical mitigation, and financial strategies. This relationship holds true across household income groups and gender of the household head and is robust. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.