Vehicle License Tax Act Article 13

The owner or user of the licensed transportation equipment, who does not intend to use the transportation equipment, shall apply to the traffic management authority for suspension of use. The tax amount for the period of use shall be calculated based on the actual number of days of usage. Upon resuming usage, the tax amount shall be calculated by subtracting the tax amount for the elapsed period from the annual tax amount.The transportation equipment that do not apply for suspension of use shall be deemed as continued usage, and the Vehicle license tax shall continue to be levied in accordance with this Act.
中文原文 使用牌照稅法第13條
交通工具所有人或使用人對已領使用牌照之交通工具,不擬使用者,應向交通管理機關申報停止使用,其已使用期間應納稅額,按其實際使用期間之日數計算之;恢復使用時其應納稅額,按全年稅額減除已過期間日數之稅額計算之。
交通工具未經所有人或使用人申報停止使用者,視為繼續使用,仍應依法課徵使用牌照稅。

English translation for reference only; the Chinese text prevails. Not legal advice.