How to identify the authenticity of forged IOUs by signature?

How to identify the authenticity of forged IOUs by signature? First, verify the actual flow of funds. In economic exchanges, any capital flow will inevitably lead to financial traces. Especially for large cash flows, both enterprises and individuals generally involve financial institutions such as banks. If the parties deposit and withdraw money in the bank, then the bank will have receipts and payments. Therefore, the judge can investigate and verify the relevant finances according to the application, or ask the parties to provide relevant settlement vouchers. In the lawsuit, the parties propose that it is a cash transaction, and the judge may conduct a detailed investigation or inquiry on the time, place and witnesses of the transaction, and may require the parties to provide witness testimony, cash sources, bills of lading and other evidence. The second is to make comprehensive judgments and form inner conviction. When the evidence presented by both parties is "equivalent" or uncertain, and it is difficult to judge whether the loan really exists based on some important evidence, the judge should give full play to his subjective initiative, restore the truth as much as possible, and make a comprehensive judgment according to the parties' ability to pay, trading habits, previous cooperative relations, loan amount and other factors to form inner conviction. The third is technical appraisal. Technical appraisal is the most direct and effective method to judge the authenticity of IOUs. During the trial of the case, some defendants argued that the IOUs were forged, the fingerprints were not stamped by themselves, and the seals were fake. In this case, the judge should inform the defendant of his rights and obligations to apply for judicial expertise within a time limit. If he fails to do so within the time limit, his claim will be deemed invalid. Where an application for appraisal is made, the facts of the case shall be determined according to the appraisal conclusion. Although technical appraisal can effectively judge the authenticity of IOUs, it has great limitations. Due to the lack of comparative samples, many IOUs are unrecognizable. In private lending, the general borrower should issue an iou to the lender to prove the fact of the loan and make an agreement on the relevant matters of the loan. Under normal circumstances, IOUs can fully prove the fact of borrowing. In the lawsuit, as long as the lender issues the loan, it has already completed the burden of proof. If there are no special circumstances, the evidential effect of IOUs should be recognized. However, in practice, there are some outstanding problems in private lending. If you don't grasp it well, your own problems will be very prominent. Therefore, such problems need to be identified, but corresponding legal procedures must be taken. Relying on legal means to safeguard their legitimate rights and interests is conducive to their own interests from being infringed.