A GST Bill book which is also known as a GST Invoice is a list of goods sent or the service offered with the amount due for payment. The GST bill book model comes with fields to enter the information of your own organization’s details. Free professional GST bill book samples are available to create invoices and can also customize them based on your requirements without any cost. Many websites offer GST Bill Book Design and Templates in Word, Docs, Sheets, Excel, and PDF.