Is it effective to put a fingerprint on the IOU or IOU? I don't know what to do if I press it.

1. Pressing the fingerprint means knowing the contents of the IOU or IOU and agreeing, which has legal effect.

If there is enough evidence to prove that the IOU or IOU was signed unwittingly, then the IOU or IOU is invalid.

2. General Principles of Civil Law of People's Republic of China (PRC)

Article 58 The following civil acts are invalid:

(1) It is committed by a person without capacity for civil conduct;

(2) A person with limited capacity for civil conduct cannot independently implement it according to law;

(3) One party makes the other party act against its true meaning by means of fraud, coercion or taking advantage of others' danger;

(4) Malicious collusion that harms the interests of the state, the collective or a third party;

(5) Violating laws or public interests;

(six) the economic contract violates the mandatory plan of the state;

(seven) to cover up illegal purposes in a legal form.

An invalid civil act is not legally binding from the beginning.