Customer invoice will not be signed back? Is there any good way?

Number the receipt, print it out formally, and sign the fax lottery. Those little girls who do accounting or purchasing believe this. The winning number can be found on your company's website, so you should always let them win the prize. Things can be smaller and do what girls like, hehe.

All the above ideas, but the general company will not implement them, because there is no consciousness of signing back, and you are too lazy to sign back other people's invoices yourself, right, hehe. In most cases, I will sign back.

Do a good job of customer relationship at ordinary times, and emphasize the importance of signing off again. This is the only way.