Access by KAI experienced a decline in customer loyalty which resulted in increased negative reviews by reliability, perceived ease of use, perceived security and customer satisfaction. The objective of this study are investigate whether reliability, perceived ease of use and perceived security have partial and simultaneous influence on customer satisfaction and customer loyalty. In this research, the writer used quantitative, descriptive, causal research design and path analysis. The sampling technique used was purposive sampling. The sample size was 97 respondents. The data collection technique used was distributing questionnaires. The statistical method used was descriptive statistics and Partial Least Square (PLS) with SmartPLS version 3.0 software.The results of hypothesis test showed that reliability a positive influence towards customer satisfaction, perceived ease of use a positive influence towards customer satisfaction, perceived security a positive influence towards customer satisfaction, perceived security have influence towards customer satisfaction, reliability a positive influence towards customer loyalty, perceived ease of use a positive influence towards customer loyalty, perceived security no influence towards customer loyalty, customer satisfaction a positive influence towards customer loyalty, reliability, perceived ease of use, perceived security and customer satisfaction have influence towards customer loyalty, customer satisfaction mediate the influence of reliability, perceived ease of use and perceived security has influence towards customer loyalty.Recommendations for Access by KAI applications can also add information on exhausted tickets or remaining ticket quotas for an area, innovates by removing unnecessary ones so that the application is not too heavy which can trigger bugs every time and improve with the use of eye or finger scans for each transaction so that it is more efficient and more in line with the times. / Access by KAI mengalami penurunan loyalitas pelanggan yang berakibat pada meningkatnya review negatif oleh reliability, perceived ease of use, perceived security dan customer satisfaction. Penelitian ini bertujuan untuk mengetahui apakah keandalan, persepsi kemudahan penggunaan dan persepsi keamanan berpengaruh secara parsial dan simultan terhadap kepuasan pelanggan dan loyalitas pelanggan. Dalam penelitian ini, penulis menggunakan desain penelitian kuantitatif, deskriptif, kausal dan analisis jalur. Teknik pengambilan sampel yang digunakan adalah purposive sampling. Jumlah sampel sebanyak 97 responden. Teknik pengumpulan data yang digunakan dengan menyebar kuesioner. Metoda statistik data yang digunakan adalah statistik deskriptif dan Partial Least Square (PLS) dengan program SmartPLS versi 3.0 Hasil uji hipotesis menunjukkan bahwa reliability memiliki pengaruh positif terhadap customer satisfaction, perceived ease of use memiliki pengaruh positif terhadap customer satisfaction, perceived security memiliki pengaruh positif terhadap customer satisfaction, perceived security memiliki pengaruh terhadap customer satisfaction, reliability memiliki pengaruh positif terhadap customer loyalty, perceived ease of use memiliki pengaruh positif terhadap customer loyalty, persepsi keamanan tidak memiliki pengaruh terhadap loyalitas pelanggan, kepuasan pelanggan memiliki pengaruh positif terhadap loyalitas pelanggan, keandalan, persepsi kemudahan penggunaan, persepsi keamanan dan kepuasan pelanggan memiliki pengaruh terhadap loyalitas pelanggan, kepuasan pelanggan memediasi pengaruh keandalan, persepsi kemudahan penggunaan dan persepsi keamanan memiliki pengaruh terhadap loyalitas pelanggan. Rekomendasi untuk aplikasi Access by KAI juga dapat menambahkan informasi tiket yang habis atau sisa kuota tiket untuk suatu daerah, melakukan inovasi dengan menghilangkan yang tidak perlu agar aplikasi tidak terlalu berat yang dapat memicu terjadinya bug setiap saat dan meningkatkan dengan penggunaan scan mata atau jari untuk setiap transaksi sehingga lebih efisien dan lebih sesuai dengan perkembangan zaman.