The Act Governing Savings Accounts for Future Education and Development of Children and Youth Article 14

The child and youth savings account interest shall be calculated at the floating board rate for one-year time savings deposits, as set by the account handling institution, and shall be exempt from individual income tax. The account handling institution is not required to withhold and declare income tax.The savings interest incurred from the 18th birthday of the account applicant until the day when the account is settled and savings are withdrawn shall be calculated at the floating board rate for demand savings deposits, as set by the account handling institution, and shall be subject to individual income tax. The account handling institution shall withhold and declare income tax when paying such interest.
中文原文 兒童及少年未來教育與發展帳戶條例第14條
兒少教育發展帳戶之利息依承辦機構一年期定期儲蓄存款一般牌告機動利率計算,並免納綜合所得稅;承辦機構並免辦理所得稅扣繳及申報。
開戶人之帳戶存款自滿十八歲之日起至辦理結清帳戶提領之日止之利息,依承辦機構牌告活期儲蓄存款機動利率計算,並應繳納綜合所得稅;承辦機構於給付利息時,應辦理所得稅扣繳及申報。

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