GST Invoice Format: Mandatory Fields Every Indian Business Must Include

A GST invoice is more than a payment request – it is a legal tax document that lets your client claim Input Tax Credit (ITC). Missing a mandatory field can cause the recipient to lose their credit and trigger queries from tax authorities.

1. Mandatory Fields on a GST Invoice

• Invoice number and date of issue.
• Supplier name, address, and GSTIN.
• Recipient name, address, and GSTIN (if registered).
• HSN code and description for each item.
• Quantity, unit, taxable value, and rate.
• CGST and SGST for intra-state sales, or IGST for inter-state sales.
• Place of supply and state name.
• Total invoice value and whether it is in rupees.

2. CGST + SGST vs IGST

When the buyer and seller are in the same state, split the tax into CGST and SGST (for example 9% + 9%). When the supply crosses state borders, charge a single IGST (for example 18%). Getting this right is essential for a valid claim of Input Tax Credit.

3. Digital Invoicing and GSTR Returns

Your invoices must reconcile with your GSTR-1 outward supply returns and your recipient’s GSTR-2B. Clean, complete invoices make monthly filing fast and reduce mismatches.

Generate a GST-compliant invoice with automatic CGST/SGST/IGST calculation using our free Invoice Generator. For reversed transactions, learn how GST credit notes keep your returns accurate.