Legal analysis: As long as it can be proved that I signed for it, it is generally valid. IOUs, IOUs and receipts are common items in life and work. Although there is a word difference between these three articles, their legal meanings are far from each other. An iou is a certificate issued by the debtor to the creditor indicating that he still owes something or a sum of money, which is generally used to prove the relationship between creditor's rights and debts. An iou is a certificate issued by the lender to the borrower or the borrower indicating that something or a sum of money is lent, which is generally used to prove the loan relationship; A receipt is a certificate issued by the receiver to the sender to show that something or a certain amount has been received, which is used to reflect or prove the fact of "receipt".

Legal basis: Article 675 of the Civil Code of People's Republic of China (PRC) stipulates that the borrower shall repay the loan within the agreed time limit. If the term of the loan is not agreed or clearly agreed, and cannot be determined according to the provisions of Article 510 of this Law, the borrower may return it at any time; The lender may urge the borrower to return it within a reasonable period of time.