IC cards are used to record the purchase information of VAT invoices, record the detailed invoicing information of VAT invoices, and securely transfer data between the enterprise's tax control invoicing system and tax control management agencies. a carrier. Within the specified date (1st to 15th of each month (postponed by holidays)), taxpayers can use the IC card to copy the tax return. They can use the remote copying system or take the IC card to the tax terminal in the National Tax Hall to complete the corresponding declaration data and use the invoice. The data is transmitted to the tax control cash register management system of the tax authority. The tax authority transmits the enterprise's tax information and tax control cash register monitoring information back to the tax control cash register and tax control financial tax card through the user card. .