According to relevant information, the loss of the original IOUs may be invalid. If the borrower does not admit the authenticity of the copy, or although he admits the authenticity of the copy, he does not admit that the money in the loan note has not been returned, then the borrower does not have to bear the repayment responsibility.

An IOU is a written document indicating the relationship between creditor's rights and debts, which is generally written and signed by the debtor, indicating that the debtor has owed the creditor the amount indicated in the IOU.