Purpose: Reducing annual report disclosure complexity has been a topic of serious debate for standard setters in recent years. In response to that, this study seeks to explore the effect of reducing such complexity on ERC, agency costs, proprietary costs, as well as interest rates on loans given by banks. Methodology: Based on listed companies in Indonesia for the year 2016, required data is collected through the IDX website. All empirical results in this study are obtained through the IBM SPSS Statistics software version 23 using the linear regression function for each hypothesis. Findings: The overall empirical results show that: 1) ERC and proprietary cost is not significantly affected by fog index, suggesting a less effective capital market in Indonesia, where information is not immediately processed in the market; 2) Agency costs are inversely related to disclosure complexity, suggesting that firms producing simpler reports are either mostly involved in tax planning, or larger Indonesian firms with lower fog usually bear higher monitoring costs; and 3) Interest rates on loans given by banks are greatly affected by disclosure complexity. Firms with more complex reports tend to get lower rates on bank loans as compared to those with much more readable reports, suggesting that providing debtholders with more complex information actually reassure them to offer lower rates. Originality: This paper is the first to explore the costs and benefits of reducing disclosure complexity in Indonesia.