Vehicle License Tax Act Article 10

The Vehicle license tax shall be collected within one month starting from April 1st of each year. However, for commercial vehicles, one half of the tax amount shall be collected within one month starting from April 1st, and the other half of the tax amount shall be collected within one month starting from October 1st of each year, based on the applicable tax amount.Prior to the commencement of the collection of the Vehicle license tax, the competent tax authority shall issue the tax payment notice to the owners or users of the transportation equipment, and shall separately announce the applicable tax amounts and the commencement and end dates of the tax collection for various types of transportation equipment.
中文原文 使用牌照稅法第10條
使用牌照稅於每年四月一日起一個月內一次徵收。
但營業用車輛按應納稅額於每年四月一日及十月一日起一個月內分二次平均徵收。
主管稽徵機關於開徵使用牌照稅前,應填發使用牌照稅繳款書送達交通工具所有人或使用人,並將各類交通工具應納之稅額及徵稅起訖日期分別公告之。

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