Agent-based financial services have become an important strategy to expand financial inclusion in rural areas, including Mandailing Natal Regency, North Sumatra. This study aims to analyze the effect of service quality and trust on customer loyalty with customer satisfaction as a mediating variable at Mandiri Link Agent UD. Naimah. This research employs a quantitative approach with a census sampling technique involving 127 active customers. Data were collected using a closed-ended Likert scale questionnaire and analyzed through descriptive statistics and hypothesis testing. The results show that service quality, trust, and customer satisfaction have a positive and significant effect on customer loyalty. The average service quality score is 32.74 (TCR 84.67%), trust is 24.54 (TCR 82.6%), and customer satisfaction is 20.76 (TCR 82.6%), while customer loyalty averages 19.50 (TCR 76%). Other findings indicate that customer satisfaction mediates the relationship between trust and customer loyalty. In conclusion, continuous improvement of service quality and strengthening customer trust are necessary to enhance customer satisfaction and loyalty. The practical implication of this study is expected to provide input for Mandiri Link Agent UD. Naimah’s management in formulating service strategies that emphasize reliability, speed, security, and transaction convenience to maintain customer loyalty amid increasingly tight digital competition.