Legal analysis: Whether the IOU is valid or not depends on whether the person signing on behalf of the enterprise belongs to the duty behavior and has sufficient authority. With the signature of the person in charge, the unit shall bear the repayment responsibility according to law, which is valid.

Legal basis: Article 465 of the Civil Code of People's Republic of China (PRC). Contracts established according to law are protected by law. A legally established contract is legally binding only on the parties, except as otherwise provided by law.