Enforcement Rules of Stamp Tax Act Article 6

The "debt notes sent out for claim of payments" depicted in Item 4, Article 6 of the Act shall mean a call notice stating the amount owed that is issued at the time of agreed payment or customarily at the end of the year, excluding notes stating products, quantities or prices issued for payment without the additional issue of an invoice or monetary receipt.The "debt notes sent out for audit purposes" depicted in Item 4, Article 6 of the Act shall mean statements issued by money businesses or merchants to customers for checking whether there are errors in payments made or received.
中文原文 印花稅法施行細則第6條
本法第六條第四款所稱催索欠款所用之帳單,係指於約定付款時間,或依習慣於年節開列結欠數目之催帳單而言。
但開列品名、數量或價格交給顧客憑以付款,而不另立營業發票或銀錢收據者,不得視為催索欠款之帳單。
本法第六條第四款所稱核對數目所用之帳單,係指銀錢業或商號開給往來戶以便查對收付數目有無錯誤之帳單而言。

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