Abstract. Buying and selling online at this time continues to experience the dynamics of development in line with the needs of the community. One of the online buying and selling practices that are in great demand by the public today is buying and selling mobile phones through a trade-in system such as what Blibli.com does. However, there are several elements that are not in accordance with the principles of buying and selling according to sharia economic law. Based on these problems, the focus of the research is formulated in the form of questions as follows: How is the practice of trade-in on the online shopping site Blibli.com? The research method used is descriptive qualitative analysis with a normative juridical approach. The results show that the practice of buying and selling cellphones in the trade-in program on the online shopping site BliBli.com is one of the consumer services where buyers can simply do all activities at home without the hassle of going to the store directly, and the practice of buying and selling cellphones the trade-in program on the BliBli online shopping site contains a conditional contract or al-uqud al-mutaqabilah which is only valid according to Sharia Economic Law. ️ Abstrak. Jual beli online pada masa sekarang terus mengalami dinamika perkembangan seiiring dengan kebutuhan masyarakat. Salah satu praktik jual beli online yang banyak diminati masyarakat dewasa ini adalah jual beli handphone melalui system tukar tambah seperti yang dilakukan Blibli.com. Namun demikian, terdapat beberapa unsur yang belum sesuai dengan prinsip-prinsip jual beli menurut hukum ekonomi syariah. Berdasarkan permasalahan tersebut, maka fokus penelitian dirumuskan ke dalam bentuk pertanyaan sebagai berikut : Bagaimana praktik tukar tambah pada situs belanja onlie Blibli.com? Dan bagaimana tinjauan Hukum Ekonomi Syariah terhadap tukar tambah pada situs belanja online Blibli.com? Metode penelitian yang digunakan adalah deskriptif analisis kualitatif dengan pendekatan yuridis normatif. Hasil penelitian menunjukkan bahwa Praktik jual beli handphone pada program tukar tambah pada situs belanja online BliBli.com merupakan salah satu pelayanan konsumen dimana pembeli cukup melakukan segala aktifitas di rumah tanpa perlu ribet untuk pergi ke toko langsung, dan Praktik jual beli handphone pada program tukar tambah pada situs belanja online BliBli mengandung adanya akad bersyarat atau al- uqud al-mutaqabilah yang sah saja dilakukan menurut Hukum Ekonomi Syariah.