Online shopping has become an integral part of supply chain management, with a significant portion of products being returned, ranging from 11% to 40% in the US depending on the product categories (Ambilkar, Dohale et al. 2022). Returns occur for various reasons, such as deficiency, mismatched fit, opportunism, etc. (Su 2009). Furthermore, a substantial amount of online sales revenue is lost to returns, exceeding $643 billion globally (Cheng 2015) and $369 billion in the United State alone (Abdulla, Ketzenberg and Abbey 2019). Therefore, the return policy plays a crucial role in online shopping, and designing an appropriate mechanism can enhance this area. Research on returns dates back several decades, focusing on money-back guarantees and product warranties (Heal 1977). In recent years, research has shifted towards operations and supply chain management. Consequently, with sustainability concerns, our research focuses on examining the return policy, particularly for secondhand products. The aim is to design a mechanism that fosters success in online trades for these products, ultimately enhancing the utilities for both sellers and buyers.