Local Government Act Article 81
When a councilor of a special municipality, county/city councilor, or township/city representative resigns, is dismissed, or dies and the number of vacancies is not less than three-tenths of the total number of councilors or representatives or the number of vacancies within the same electoral district is not less than one half of the total, a supplementary election shall be held; however, no supplementary election shall be held if the remaining term of office is not more than two (2) years and the number of vacancies is not less than one-half of the total.Councilors of special municipalities, county/city councilors, and township/city representatives elected during the supplementary election shall only serve the remaining term of office.Resignations of councilors of special municipalities, county/city councilors, or township/city representatives in Paragraph 1 shall be submitted in writing to the council of the special municipality, county/city council, or township/city council. The resignation shall become effective once the letter of resignation is submitted to the council.
中文原文 地方制度法第81條
直轄市議員、縣（市）議員、鄉（鎮、市）民代表辭職、去職或死亡，其缺額達總名額十分之三以上或同一選舉區缺額達二分之一以上時，均應補選。
但其所遺任期不足二年，且缺額未達總名額二分之一時，不再補選。
前項補選之直轄市議員、縣（市）議員、鄉（鎮、市）民代表，以補足所遺任期為限。
第一項直轄市議員、縣（市）議員、鄉（鎮、市）民代表之辭職，應以書面向直轄市議會、縣（市）議會、鄉（鎮、市）民代表會提出，於辭職書送達議會、代表會時，即行生效。
但其所遺任期不足二年，且缺額未達總名額二分之一時，不再補選。
前項補選之直轄市議員、縣（市）議員、鄉（鎮、市）民代表，以補足所遺任期為限。
第一項直轄市議員、縣（市）議員、鄉（鎮、市）民代表之辭職，應以書面向直轄市議會、縣（市）議會、鄉（鎮、市）民代表會提出，於辭職書送達議會、代表會時，即行生效。