A: According to Item 3 of Article 2 of the Notice on Printing and Distributing in State Taxation Administration of The People's Republic of China, People's Republic of China (PRC) (Guo Shui Fa 1993 154), taxpayers sell goods with old ones for new ones, and the sales amount is determined according to the sales price of new goods in the same period. Therefore, if the goods are sold in a trade-in way, an invoice should be issued and the tax should be calculated according to the sales price of the goods in the same period. When collecting secondhand goods, the input tax indicated on the special VAT invoice can be deducted.
Special case: for the trade-in business of gold and silver jewelry, VAT can be levied according to the total price actually charged by the seller excluding VAT. So if you only accept the price difference, you can determine the sales amount according to the price difference.