If you're a GST-registered business, every sale needs a proper GST (tax) invoice. It's not complicated once you know the steps — but miss a required detail and your customer's input-tax credit (and your own records) can go wrong. Here's exactly how to create a GST invoice, step by step.
What counts as a GST invoice?
A GST invoice is the legal document you issue for a taxable sale of goods or services. It records what you sold, to whom, and how much tax applies — and it's what your buyer uses to claim input-tax credit (ITC). Issue it at the right time: for goods, on or before delivery/dispatch; for services, within 30 days of providing them.
Step 1 — Add your business details
At the top, include:
- Your business name, address and GSTIN
- A unique invoice number (a continuous serial for the financial year)
- The invoice date
Step 2 — Add the customer's details
- Customer name and address
- Their GSTIN (for B2B sales — this is what lets them claim ITC)
- Place of supply (the state) — this decides which tax applies (see Step 4)
Step 3 — List the items or services
For each line, show:
- Description of the goods/service
- HSN code (goods) or SAC code (services) — how to find your HSN code
- Quantity, unit and rate
- Taxable value (before tax)
Step 4 — Apply the right GST
This is where most mistakes happen. The tax type depends on where the customer is:
- Same state (intra-state): split the GST into CGST + SGST (e.g. 18% = 9% CGST + 9% SGST)
- Different state (inter-state): charge a single IGST (e.g. 18% IGST)
Apply the correct rate for each item's HSN, show the tax amount per line, and total it up.
Step 5 — Show totals and finish
- Taxable value, total tax (CGST/SGST or IGST), and grand total
- A declaration and your signature (or digital signature)
- If applicable, e-invoice (IRN) and QR code, and an e-way bill for goods above the threshold
For the full list of mandatory fields, see our GST invoice format guide.
Common mistakes to avoid
- Wrong tax type — charging CGST/SGST on an inter-state sale (or IGST on a local one). Place of supply decides it.
- Missing or wrong GSTIN — the buyer can't claim ITC, and it causes reconciliation mismatches.
- Broken invoice numbering — numbers must be continuous and unique for the year.
- Wrong HSN/rate — leads to the wrong tax amount.
- Issuing late — especially for services (30-day rule).
The fast way: let software do it
Doing all this by hand in Excel is slow and error-prone — and you still have to total the tax, track numbering, and build your GST returns later. Billing software handles it for you: pick the customer and items, and the tax type, HSN, totals and invoice number are applied automatically, ready to print, email or share on WhatsApp. Your GST returns are then built from real data instead of re-keyed.
That's exactly what CraveInvoice does — raise a correct GST invoice in seconds, with CGST/SGST/IGST, e-invoice and e-way bill handled. See GST accounting software or invoice software, or start a free trial and make your first invoice today.