Psychologists Act Article 50

Municipal and county (city) clinical psychologist guilds or counseling psychologist guilds shall be founded and organized by 9 or more clinical psychologists or counseling psychologists in the jurisdiction, respectively. If there are less than 9 psychologists, such psychologists may join the guild in the neighboring area.
中文原文 心理師法第50條
直轄市、縣(市)臨床心理師公會或諮商心理師公會,由該轄區域內臨床心理師、諮商心理師各九人以上發起組織之;其未滿九人者,得加入鄰近區域之公會。

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