Trust transfer theory posits that trust can be transferred from the selling platform to the sellers and has been widely applied in the e-commerce environment. However, prior research has overlooked the boundary conditions under which trust can be transferred. Understanding of the general institutional mechanisms is necessary to ensure the trust environment underlying e-commerce. The present study identifies two key moderators that affect the relationships between trust-in-platform, trust-in-seller, and purchase intention in consumer to consumer (C2C) online shopping contexts: perceived effectiveness of e-commerce institutional mechanisms (PEEIM) and perceived website quality of the seller (PWQS). Using a sample of 294 online buyers from TaoBao (a major Chinese C2C portal), we find that trust-in-platform positively affects trust-in-seller; meanwhile, trust-in-seller positively influences purchase intention. In addition, PEEIM negatively moderates the relationship between trust-in-platform and trust-in-seller, whereas it positively moderates the relationship between trust-in-seller and purchase intention. PWQS positively moderates the relationship between trust-in-platform and trust-in-seller but negatively moderates the relationship between trust-in-seller and purchase intention. Our findings complement trust transfer theory by demonstrating how PEEIM and PWQS have different moderating effects on the trust transfer process. For C2C platform providers and sellers, the findings suggest that they should strategically build buyers trust according to different levels of PEEIM and PWQS in order to promote buyers purchasing behavior.