This paper investigates how the supplier's bargaining power affects trade credit supply. We use a novel firm-level database of Chinese firms with unique information on the amount, terms, and payment history of trade credit extended to customers and detailed information on product market structure and clients-supplier relationships. We document that suppliers with weak bargaining power towards their customers are more likely to extend trade credit, have a larger share of goods sold on credit, and offer a longer payment period before imposing penalties. Important customers extend the payment period beyond what has been offered by their supplier and generate overdue payments. Furthermore, weak bargaining power suppliers are less likely to offe...