This study analyzes the effect of customer complaints on the securities firm’ value and the value relevance of customer deposits, a common indicator of customer-related intangible assets in securities firm. The analysis results are as follows: Firstly, the analysis of the relationship between customer complaints and firm value showed a statistically significant negative correlation. This suggests that a high level of customer complaints, representing dissatisfaction with customer service, has a negative effect on firm value. Secondly, the customer complaints differentiates the value relevance of customer deposits. Specifically, the value relevance of customer deposits is enhanced where there are many customer complaints. This emphasizes the need to consider not only the direct effect of customer complaints on firm value but also their indirect effect on customer-related intangible assets. This research uniquely estimates the economic meaning of customer complaints on securities firms, examining them empirically, differentiating it from previous studies.