The amount of business tax payable or overpaid by a business entity will be the difference between the output tax in a tax period and the input tax in the same period.
The amount of business tax returned by a business entity to a purchaser due to sales return of goods or rebates allowed shall be deducted from output tax in the tax period when the return or rebate occurs. The amount of business tax received by a business entity due to the business entity's return of purchased goods, or due to an allowance on purchased goods, shall be deducted from the amount of input tax in the tax period when such return of goods or allowance occurs.
The input tax is defined as the business tax paid by a business entity in accordance with the act at the time of purchasing goods or services.