Clacify

GST Invoice Generator

Generate GST-compliant invoices with CGST/SGST/IGST and download as PDF

Built & maintained by Pappu Venkata Subbi Reddy, founder of Clacify · Updated July 2026 · Formulas verified against official Indian government sources

About GST Invoice Generator

GST Invoice Generator creates professional, GST-compliant invoices for Indian businesses and freelancers — free, with no subscription. Enter your business and customer details, add line items with HSN/SAC codes and GST rates, and the tool calculates CGST + SGST (intra-state) or IGST (inter-state) automatically, then lets you download a clean PDF invoice. It covers the mandatory fields required under GST rules, so your invoices are valid for input tax credit. Your billing data is processed in your browser and never uploaded to a server.

Why Use GST Invoice Generator?

How It Works

For each line item, tax = taxable value × GST rate. For intra-state supply the GST is split equally into CGST and SGST (e.g. 18% → 9% + 9%); for inter-state supply the full rate is charged as IGST. The tool totals the taxable value, tax, and grand total, lays them out in a GST-compliant invoice format with all mandatory fields, and renders it to a downloadable PDF in your browser. No billing data is sent to any server.

What a GST tax invoice must include (Rule 46, CGST Rules)

FieldNotes
Supplier detailsName, address and GSTIN
Invoice number & dateUnique, consecutive, up to 16 characters
Recipient detailsName, address and GSTIN (if registered)
HSN / SAC codeHSN for goods, SAC for services
Description, qty, valueItem, quantity, unit and taxable value
GST breakupCGST + SGST, or IGST — with rate and amount
Place of supplyRequired for inter-state (IGST) supplies
SignaturePhysical or digital signature of the supplier

This generator lays out all of these automatically. Miss any and the invoice isn't valid for your buyer's input tax credit.

CGST + SGST or IGST — which to charge

It depends on the place of supply, not where you're registered. If the supplier and the customer are in the same state (intra-state), you split the GST into CGST + SGST — an 18% rate becomes 9% + 9%. If they're in different states (inter-state), you charge the full rate as a single IGST. Getting this wrong is the most common invoicing mistake and can block your customer's input tax credit, so the place of supply must be stated correctly.

HSN/SAC codes and how many digits you need

Every product needs an HSN code and every service a SAC code — they tell the tax system exactly what's being sold. How many digits you must show depends on turnover: businesses with turnover up to ₹5 crore generally show 4-digit HSN on B2B invoices, and those above ₹5 crore show 6 digits. Putting the right code (and enough digits) on the invoice keeps it compliant and makes GST return filing straightforward.

When you need e-invoicing (and when a bill of supply)

Since businesses crossing ₹5 crore annual turnover must generate e-invoices — uploading each B2B invoice to the government portal to get an IRN and QR code — a plain PDF isn't enough for them. Below that threshold, a standard GST invoice like this one is fine. Note the exceptions: composition-scheme dealers and suppliers of exempt goods issue a "bill of supply" (no tax charged) instead of a tax invoice.

Frequently Asked Questions

How to create a GST invoice online free?

Fill in your business name and GSTIN, your client's details, add line items with descriptions, HSN/SAC codes, quantities, rates, and GST percentage. The tool automatically calculates CGST+SGST (intra-state) or IGST (inter-state). Click 'Download PDF' to get a professional invoice — no sign-up needed.

What is the difference between CGST, SGST, and IGST?

For supplies within the same state (intra-state): GST is split equally into CGST (Central GST) and SGST (State GST). For example, 18% GST = 9% CGST + 9% SGST. For supplies between different states (inter-state): only IGST (Integrated GST) applies at the full rate (e.g., 18% IGST). Clacify detects this automatically from the state code in your GSTINs.

Related Finance Tools