Act Governing Relations with Hong Kong and Macau Article 8

The Executive Yuan may allow the Hong Kong or Macau government, or their respective authorized non-governmental organizations, to set up establishments in and dispatch representatives to the Taiwan Area to handle matters regarding exchanges between the Taiwan Area and Hong Kong or Macau.Personnel of said establishments must be residents of Hong Kong or Macau.
中文原文 香港澳門關係條例第8條
行政院得許可香港或澳門政府或其授權之民間團體在臺灣地區設立機構並派駐代表,處理臺灣地區與香港或澳門之交流事務。
前項機構之人員,須為香港或澳門居民。

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