An iou is valid without a signature. The IOU is not printed by hand, but it is also valid to have the debtor's autograph. According to the law, IOUs should be in written form, and the contents of IOUs generally include terms such as the type, currency, purpose, amount, interest rate, term and repayment method. Therefore, the IOU is valid as long as it has the contents of the above provisions and has the personal signature of the debtor. Legal objectivity:

Article 143 of the Civil Code of the People's Republic of China is valid for a civil juristic act that meets the following conditions: (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 2 of the Civil Code of the People's Republic of China * * * Minors under the age of eight are persons without capacity for civil conduct, and their legal representatives shall act as agents to carry out civil legal acts.