To put it simply, firstly, the name of the other party (payer) must be written clearly; secondly, if it is a sales invoice for goods, write down the name of the goods, unit price, quantity and amount; if it is a service industry invoice, write down the name of the project. For example, accommodation fees, advertising fees, etc. vary according to different industries. Third, the date and the issuer must be clearly stated. The fourth is to stamp the company's special financial seal or special invoice seal. Be careful not to alter it.