Regulations Governing the Use of Cash Register by Business Entities Article 7
A business entity which uses cash registers to issue uniform invoices should purchase duplicate and triplicate copies of uniform invoices when sending a salesperson to sell goods outside its fixed place of business. The salesperson should bring and issue the aforesaid uniform invoices to the buyer at the time of sale.
中文原文 營業人使用收銀機辦法第7條
使用收銀機開立統一發票之營業人派出推銷人員攜帶貨物離開營業場所銷售者，應另行購用二聯式、三聯式統一發票，由推銷人員於銷售貨物時開立交付買受人。