Enforcement Rules of the Income Tax Act Article 47
Where a profit-seeking enterprise conducts installment payment sales by adopting the gross profit percentage method to calculate losses and profits, its creditor’s right receivable shall not include the bad debts for offset: When the price difference apportion method or the common sales method is adopted, the above rule is also applicable to the price for installment payments recorded on the contract and the creditor's right to the difference on the current sales price.
中文原文 所得稅法施行細則第47條
營利事業分期付款銷貨採毛利百分比法計算損益者，其應收債權，不得提列備抵呆帳；採差價攤計法或普通銷貨法者，其約載分期付款售價與現銷價格之差額部分之債權，亦同。