Legal analysis: IOUs may not be protected by the guarantor. Writing the name of the guarantor on the IOU is only a guarantee to ensure the realization of the creditor's rights. Whether there is a guarantor or not does not affect the legal effect of the loan, but the loan must be written by the borrower voluntarily, and the content of the loan cannot violate the mandatory provisions of laws and administrative regulations. The loan amount and the borrower's name should be stated on the loan slip, and if there is a guarantor, the personal information of the guarantor should also be written.

Legal basis: Provisions of the Supreme People's Court on Several Issues Concerning the Application of Laws in the Trial of Private Lending Cases Article 21 If someone else signs or seals the creditor's rights certificate or loan contract such as IOUs, receipts and IOUs, but fails to show that he is the guarantor or assumes the guarantee responsibility, or cannot be presumed as the guarantor through other facts, and requests him to assume the guarantee responsibility, the people's court will not support it.