Identifying the credit risk of borrowers residing in lower-tier cities and rural areas remains a critical challenge for commercial banks to improve inclusive finance. Based on the data of an online lending platform affiliated with a commercial bank in Hunan Province, this study evaluates the information content of relationship score and its impact on the credit risk assessment. Empirical results demonstrate that relational information significantly enhances the accuracy of credit risk assessments for borrowers located in lower-tier cities and rural areas, and this effect operates primarily through a constraint mechanism. At the same time, relational information enhances the information content of credit risk assessment by mitigating gaps in traditional credit data and revealing borrowers risk preferences. This study reveals the influence mechanism and operational pathways of bank relational information in the context of “inclusive finance+digital finance”, which provides support for advancing high-quality development in Chinese financial sector.