The buyer privately signed an iou with the merchant. In fact, he has returned to the company with the reimbursement receipt for purchasing materials! How does the law solve this problem?

If the merchant clearly knows that the buyer has no right to sign the white note and still accepts the white note, the company will not be responsible, and the merchant will ask the buyer for it.

If the merchant doesn't know, it constitutes an agency by estoppel, and the company should pay the payment to the merchant according to the debt. Then claim the payment from the buyer and punish according to the company's internal management regulations. If the amount is relatively large, you can also report the criminal responsibility of the buyer and be suspected of misappropriating funds.

If the buyer obtains funds for the purpose of possession, the large amount constitutes the crime of occupational embezzlement. The company reported the case and investigated its criminal responsibility according to law, and recovered the embezzled money.