There is no contract, but is there a delivery note signed by the other party for receipt of the goods? Or a statement signed or stamped by both parties? In addition, if the transaction between the two parties is reached through email or confirmed via WeChat, SMS, QQ, etc., these can be used as actual evidence to support the transaction between the two parties. If the other party refuses to pay for the goods, you cannot verbally urge the other party to pay for the goods. It is recommended. It is recommended that you communicate with the other party via email to confirm the payment and urge the other party to pay within a certain period of time. As long as the other party confirms receipt of your goods and admits that it still owes you the payment, these are all evidence. After obtaining this evidence, you can ask a lawyer to send a lawyer's letter to demand payment, or you can file a lawsuit in court.