If the sales discount is reflected in the invoice, the value-added tax is calculated according to the discounted price, that is to say, if it is 20% off, the amount that should be paid with value-added tax is also 20% off the original price. If it is not reflected in the value-added tax invoice, the value-added tax of the discounted part will still be paid, and its sales will be calculated and paid according to the amount on the value-added tax invoice.

Therefore, it is suggested to reflect the sales discount on the VAT invoice and add this item.