Regulations Governing Enrollment in Postal Simple Life Insurance Policies Article 13

Within the effective period of insurance, the proposer may make changes to the insurance contract. The period of insurance and the period of payment may not be longer than what’s specified in the original contract. In the case of applying to change the amount insured, the amount may not be higher than the original contract or lower than the amount required. For contracts whose premiums have been paid over a year, the proposer may change it into paid-up insurance with a reduced lump sum payment.When applying for any of the aforementioned, a contract change form shall be filled out and given to the insurance handling branch along with the policy.
中文原文 郵政簡易人壽保險投保規則第13條
要保人於契約有效期間內得申請變更保險契約,申請變更之保險期間及付費期間,不得長於原契約所訂者;申請變更保險金額者,其金額不得高於原契約所訂者,亦不得低於規定之最低保險金額。
保險費已付足一年以上者,得申請變更為減額繳清保險契約。
前項申請,應填具契約變動通知書,連同保險單一併送交經辦郵局辦理。

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