A Purchase Invoice is a bill you create against the supplier to purchase a product. This is the invoice’s key purpose of creating a paper trail between the buyer and the seller, and also sending, receiving, and settling invoices proves that both parties are communicating. In contrast, an invoice’s itemized nature keeps your business dealings transparent. Making a Purchase Invoice is very similar to making a Purchase Order. With this option, users can also add a new product by product master, enter the quantity, MRP, sale rate, cash discount, etc.