GST or the Goods and Services Tax is an upcoming tax system that is expected to replace several currently levied indirect taxes with a single tax. This tax will be applicable across India and will be levied on all goods and services.A GST invoice is a document which is supposed to contain all the relevant details of a business transaction and both the parties involved. It must comprise of the product name, description, quantity, details of the supplier and the purchaser, terms of sale, rate charged, discounts, etc. Supporting documents under GST are sales invoices, purchase invoices, bill of supply, credit notes, debit notes, receipts, vouchers.

Above screenshot represents the sale invoice in that bill invoice calculated the gst tax amount and given to the customers.