Regulations Governing the Use of Uniform Invoices Article 20-1

When a business entity sells goods or services and issues an electronic uniform invoice, and subsequently both the seller and the purchaser agree to a sales return or allowance, or a purchase return or allowance, the entity shall issue, transmit, or receive the Certificate of Sales Return, Purchase Return, or Allowances via the Internet or other electronic means. The relevant files shall include the retention media file, the receipt media file, and the certification media file. The purposes of these files are as follows:1. Retention Media File: To be retained by the seller business entity and used as an accounting voucher and for declaring deductions of output tax in accordance with the provisions of the Act.2. Receipt Media File: To be provided to the purchaser as a receipt and, where the purchaser is a business entity, used as an accounting voucher and for declaring deductions of input tax in accordance with the provisions of the Act.3. Certification Media File: To be transmitted by the seller business entity to the Platform for certification.The seller business entity may download and print the Certificate of Sales Return, Purchase Return, or Allowances in the prescribed format from the retention media file to serve as an accounting voucher and for declaring deductions of output tax. The purchaser business entity may download and print the Certificate of Sales Return, Purchase Return, or Allowances from the certification media file on the Platform, to serve as an accounting voucher and for declaring deductions of input tax.
中文原文 統一發票使用辦法第20-1條
營業人銷售貨物或勞務,於開立電子發票後,經買賣雙方合意銷貨退回或折讓、進貨退出或折讓,應以網際網路或其他電子方式開立、傳輸或接收銷貨退回、進貨退出或折讓證明單,其應有存根檔、收執檔及存證檔,用途如下:
一、存根檔:由賣方營業人自行保存,作為記帳憑證及依本法規定申報扣減銷項稅額之用。
二、收執檔:交付買受人收執,其為營業人者,作為記帳憑證及依本法規定申報扣減進項稅額之用。
三、存證檔:由賣方營業人傳輸至平台存證。
賣方營業人得自存根檔或買受人為營業人者得自平台存證檔,依規定格式下載列印銷貨退回、進貨退出或折讓證明單,作為申報扣減銷項稅額、進項稅額或記帳之憑證。

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