Labor Insurance Act Article 58-2

Insured persons who have conformed with the old-age benefit claiming criteria in first subparagraph of first paragraph and fifth paragraph of article 58 but have postponed in claiming the old-age pension benefit, extra 4% of the pension benefit amount calculated using the method in preceding article will be granted for each year of pension benefit claiming postponement with the upper limit of 20% extra.An insured person who has more than fifteen years of insurance coverage but doesn't reach the claiming age stipulated in first paragraph and fifth subparagraph of article 58 could claim for old-age pension benefit within five years in advance. However, 4% of the pension benefit amount calculated using the method in preceding article will be deducted for each year of pension benefit claiming advancement with the upper limit of 20% deduction.
中文原文 勞工保險條例第58-2條
符合第五十八條第一項第一款及第五項所定請領老年年金給付條件而延後請領者,於請領時應發給展延老年年金給付。
每延後一年,依前條規定計算之給付金額增給百分之四,最多增給百分之二十。
被保險人保險年資滿十五年,未符合第五十八條第一項及第五項所定請領年齡者,得提前五年請領老年年金給付,每提前一年,依前條規定計算之給付金額減給百分之四,最多減給百分之二十。

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