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 7 of the Civil Law of People's Republic of China (PRC) shall follow the principle of good faith and adhere to the principle of good faith when engaging in civil activities.