Postal Act Article 14

Subject to approval by the competent authority, Chunghwa Post Co., Ltd may set the postages for delivery of the documents which are only allowed to be delivered by Chunghwa Post and its entrusted parties as described in paragraph 1 of Article 6. Chunghwa Post Co., Ltd may set at its discretion rates for mail items other than the ones provided in the preceding paragraph. Postage of mail items should reasonably reflect the cost and a rational profit.
中文原文 郵政法第14條
第六條第一項限由中華郵政公司或受其委託者遞送文件之資費,由中華郵政公司擬訂,報請主管機關核定後實施。
前項以外郵件之資費,由中華郵政公司自行訂定。
郵件之資費應適當反映成本及合理利潤。

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