Di SMK Maarif 1 Kalirejo, Lampung Tengah, sistem pembayaran administrasi sekolah masih menggunakan metode konvensional. Siswa mencatat pembayaran mereka secara manual di buku dan kartu pembayaran mereka. Hal ini menyebabkan banyak pekerjaan yang tidak efisien. Tujuan membangun sistem pembayaran SPP di SMK Maarif 1 Kalirejo, memudahkan dalam sistem administrasi pembayaran. Sistem ini dibangun menggunakan metodologi pengembangan software SDLC (Software Development Life Cycle), Framework Bootstrap, database MySQL, dan bahasa pemrograman PHP untuk mendesain antarmuka sistem berbasis web, serta sistem berbasis web mobile Java dan Flutter.Uji coba sistem dan produk dilakukan dalam dua tahap. Sistem berbasis web dan mobile mendapatkan skor 38, masing-masing dengan kategori sangat valid. Uji coba produk sistem mendapatkan skor 31, dengan kategori sangat efektif. Setiap proses telah disederhanakan dengan sukses, dan waktu pelayanan telah dikurangi dari sepuluh menit menjadi tiga menit dibandingkan dengan sistem sebelumnya. At SMK Maarif 1 Kalirejo, Central Lampung, the school administration payment system still uses conventional methods. Students record their payments manually in their books and payment cards. This causes a lot of inefficient work. The purpose of building a tuition payment system at SMK Maarif 1 Kalirejo is to facilitate the payment administration system. This system is built using the SDLC (Software Development Life Cycle) software development methodology, Bootstrap Framework, MySQL database, and PHP programming language to design a web-based system interface, as well as a Java and Flutter mobile web-based system. System and product trials were conducted in two stages. The web and mobile-based systems scored 38, each with a very valid category. The system product trial scored 31, with a very effective category. Each process has been successfully simplified, and service time has been reduced from ten minutes to three minutes compared to the previous system.