If you are registered for GST, every sale needs the right document. This is a plain overview, not tax advice; your chartered accountant has the last word.
Tax Invoice or Bill of Supply
A regular GST-registered seller issues a tax invoice that shows the GST charged. A seller under the composition scheme issues a bill of supply instead, without GST.
CGST and SGST, or IGST
Where the order is delivered decides the tax. Delivered within your own state: central and state GST (CGST and SGST), split equally. Delivered to another state: integrated GST (IGST).
HSN Codes
Each product has an HSN code that sets its GST rate. Getting it right matters for your returns.
Credit Notes
When an order is cancelled or refunded after its invoice, a credit note reverses it. Never edit an issued invoice.
GSTR-1
Your outward supplies are reported in GSTR-1. Your accountant needs your invoices and credit notes for the period, in order.
Mercayo makes the right document for every order, credit notes on cancellations, and exports GSTR-1 files and an invoice archive. An HSN code finder fills in the rate. See GST and invoices.