An iou can be regarded as a contract. As long as the contents of the contract are legal and the conclusion process is legal, the written pledge of IOUs is valid.

According to the law, if the parties conclude a contract in the form of a contract, they shall sign or seal it. If the parties press their fingerprints on the contract, the people's court shall determine that it has the same legal effect as the signature or seal.

legal ground

Article 490 of the Civil Code stipulates that 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.