A GST invoice must carry specific fields prescribed under the CGST Rules. Get them right the first time and your GSTR-1 flows in automatically. Here is the exact workflow we recommend, using Deccan Bill or any modern billing tool.
Step 1 — Add your business & GSTIN
In your billing tool, open Company Settings and add your registered legal name, GSTIN, PAN, state of registration and address. This is what appears at the top of every invoice. Upload your company logo and signature so they auto-embed on every PDF (see our Features page).
Step 2 — Create the customer
Enter customer name, GSTIN (for B2B), billing & shipping address, and place of supply. Deccan Bill verifies the GSTIN against the official GSTN database in real time.
Step 3 — Add products with HSN codes
Each line item needs: description, HSN/SAC, quantity, unit, rate, discount and GST rate. Deccan Bill suggests HSN based on your product name so you never have to look it up.
Step 4 — Let the software split GST
If your customer is in the same state, CGST + SGST is applied. If interstate, IGST replaces both. Composition dealers get a simpler tax line. Deccan Bill handles all three without manual toggles.
Step 5 — Review, share & get paid
Review the totals, add terms & conditions, and share via WhatsApp or email with a UPI QR embedded so your customer can pay in one tap. For step-by-step visuals, see our product walkthrough (coming soon).
Ready to try it yourself? Start free or read about GST invoice format.
Frequently asked
What is mandatory on a GST invoice?
Supplier name + GSTIN + address, invoice number, date, customer GSTIN (B2B), place of supply, HSN codes, tax rates, CGST/SGST/IGST split, taxable value and total.
Do I need a signature on the GST invoice?
Yes. It can be a digital or physical signature of the supplier or an authorised representative. Deccan Bill lets you upload a signature image that auto-embeds on every invoice.
How many digits should the HSN code be?
For turnover up to ₹5 crore, 4-digit HSN; above that, 6-digit HSN is required.
Related reading
What is GST Billing Software? A 2026 Guide for Indian Businesses
GST billing software helps Indian businesses issue GST-compliant invoices, file GSTR-1/3B and manage stock. Here is what it is, who needs it and how to choose the right one.
GST Invoice vs Tax Invoice — What's the Difference?
GST invoice and tax invoice — are they the same or different? Understand the legal difference, when to issue each, and how billing software gets it right automatically.
E-Invoice & E-Way Bill Guide — When, Why and How
Complete guide to e-Invoice (IRN) and e-Way Bill in India — who must generate them, thresholds, validity, and how modern billing software automates both.
Put this into practice
Start with a free Deccan Bill account and create your first GST-compliant invoice in under a minute.