Offshore Islands Development Act Article 10

Goods sold and delivered locally or services provided locally by business entity(entities) in the Penghu, Kinmen, Matsu, Ludao (Green Island), Lanyu, and Liuqiu areas shall be exempted from business tax.Merchandise imported and sold locally by business operators in the Penghu, Kinmen, Matsu, Ludao (Green Island), Lanyu, and Liuqiu areas shall be exempted from customs duties. The duty-free items and the method of implementation shall be prescribed by the Ministry of Finance.
中文原文 離島建設條例第10條
澎湖、金門、馬祖、綠島、蘭嶼及琉球地區之營業人,於當地銷售並交付使用之貨物或於當地提供之勞務,免徵營業稅。
澎湖、金門、馬祖、綠島、蘭嶼及琉球地區之營業人進口並於當地銷售之商品,免徵關稅;其免稅項目及實施辦法,由財政部定之。

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