Legal analysis: If the IOU is not signed or fingerprinted by both parties, it is an invalid contract in principle and has no legal effect. Unless both parties agree on a confirmation method that can prove that both parties are familiar with, recognize and perform the contents of the contract, except stamping, signing and fingerprinting. Otherwise, a contract without the seal and signature of both parties will have no legal effect because it is not established.

According to Article 490 of the General Principles of the Civil Law, if the parties conclude a contract in the form of a contract, the contract is established when the parties sign, seal or press their fingerprints. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.

A contract shall be concluded in written form as stipulated by laws, administrative regulations or agreed by the parties. If the parties do not do this in writing, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.

Legal basis: Article 490 of the Civil Code of People's Republic of China (PRC). If the parties enter into a contract in the form of a contract, the contract shall be established when the parties sign, seal or press their fingerprints. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.

A contract shall be concluded in written form as stipulated by laws, administrative regulations or agreed by the parties. If the parties do not do this in writing, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.