An iou is valid only if there is no fingerprint signature. As long as the party signing the IOU has the corresponding capacity for civil conduct, the behavior is the true intention of the parties, and it is legal and effective without violating the legal provisions or public order and good customs.

legal ground

Article 143 of the Civil Code

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.

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.