Signing a sales order is not necessarily an iou, but at most it proves that the customer has received the goods. In order to prove that the customer has received the goods but never paid for them, it is necessary to provide other evidence related to the goods, such as the customer's signature on the delivery note (mainly to confirm handwriting) and the proof that the customer paid you according to the delivery direction, so as to prove that the customer's signature on the sales note is equivalent to his signature on the sales note. The customer received the goods, but did not pay the corresponding payment, so the payment should be made according to the actual amount of the sales order. Since the invoice occurred in June 5438 +2006 10, there is still a period of time before the statutory limitation for requesting protection of civil rights from the people's court is two years. Your company may bring a lawsuit to the people's court, demanding that the customer immediately repay the arrears and interest within two years from the date of signing the sales order. You want to interrupt the limitation of action, but to support your company's claim that the limitation of action is interrupted, such as "urging him to pay back the money, but he doesn't pay it back", there must be enough evidence to prove that (for example, your company's letters urging customers to pay back the money and possible audio-visual materials) are only superficial and cannot be used as evidence.