According to the law, it has exceeded the limitation of action for 2 years and is not protected by law, but the other party still has the obligation to repay. If you formally urge the other party to repay the loan with a valid document (such as a lawyer's letter), the limitation of action will be terminated and recalculated. If your last reminder is less than 2 years, you can sue. There has been no reminder before, or it has been more than two years since the last reminder. It's no use reminding me now. Without legal protection, the collection of accounts depends entirely on the company's own ability. You can offer a reward, or you can invite someone who specializes in collecting accounts, but don't violate the law.
When confirming the sales revenue, it is correct to use the sales invoice as the original voucher. When dealing with the business of selling goods after receiving payment for goods, the sales invoice is not only a voucher for receiving money, but also a voucher for confirming income. However, since the payment was not received at that time, when the payment is received in the future, a receipt should be issued to the payer as evidence of payment delivery and as the original voucher for writing off accounts receivable. At the same time, the other party also needs your receipt as the original proof of payment.