Need to sign. The agent on the IOU is only the agent of the matter, not necessarily the debtor, but the agent must prove that he is not the owner and debtor of the property, and the agent may not bear the consequences. Article 490 of the Civil Code 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:

People's Republic of China (PRC) Civil Code

Article 143

A civil juristic act that meets the following conditions is valid:

(1) The actor has corresponding capacity for civil conduct;

(2) the meaning is true;

(three) does not violate the mandatory provisions of laws and administrative regulations, and does not violate public order and good customs.

People's Republic of China (PRC) Civil Code

Article 20

Minors under the age of eight are persons without capacity for civil conduct, and their legal representatives act as agents to carry out civil legal acts.