Income Tax Act Article 40
Where the period of business operation is under one year, the amount of income derived for such period shall first be converted into a corresponding annual income according to the proportion of the length of the period to the year, and the amount of income tax shall then be determined by the tax rate applicable to such annual income but paid on the basis of the original proportion for the period in which business is actually operated.Where the period of business operation is shorter than one month, it shall be counted as one month.
中文原文 所得稅法第40條
營業期間不滿一年者，應將其所得額按實際營業期間，相當全年之比例，換算全年所得額，依規定稅率計算全年度稅額，再就原比例換算其應納稅額。
營業期間不滿一月者，以一月計算。
營業期間不滿一月者，以一月計算。