How to Create a GST Invoice in Catalystk
A GST invoice – also called a tax invoice or GST bill – shows your GSTIN, the buyer's GST number, the HSN or SAC code of each item and the GST charged. With Catalystk's free GST billing software you can create a GST invoice online in minutes. The software calculates the tax for you: CGST + SGST for a sale within your state and IGST for a sale to another state. Then print or email it in a clean tax invoice format.
- CGST, SGST & IGST
- HSN/SAC codes
- Tax invoice PDF
- Free
Before you start: add your GSTIN in your branch settings (GST Number) so it prints on every invoice, and add the HSN or SAC code to each product once. GST taxes – CGST, SGST and IGST at each rate – are already set up as tax records.
Open Invoice and click New Invoice
Every GST invoice starts from the Invoice list.
- 1
Go to Sales → Invoice
In the left menu, open Sales and click Invoice. The list shows all your invoices.
- 2
Click New Invoice
Click the green New Invoice button at the top right. A new GST invoice form opens.
Enter the client information and GST details
A B2B tax invoice needs the customer's GST number and the place of supply.
- 3
Enter the client information
Fill in the client's name, mobile, email, company name and billing address.
- 4
Add the GST details
For a business customer, enter their GST Number, choose the Invoice Type (for example B2B) and the State Code of the place of supply.
Add items with HSN/SAC codes and GST
Catalystk calculates CGST, SGST or IGST on every line and shows the totals.
- 5
Add items with HSN/SAC codes
Pick each product, enter the quantity and rate, and check its HSN or SAC code.
- 6
Choose the GST
For a sale in your own state, add CGST and SGST – for example CGST 9 + SGST 9 for 18% GST. Catalystk shows each tax separately in the invoice totals.
Save, print or email the GST invoice
Your GST invoice is ready – it looks like the sample at the top of this page.
- 7
Save, print or send the GST invoice
Click Save, then preview, print, download the GST invoice PDF or email it to the customer.
CGST + SGST or IGST – which tax to choose?
The total GST is the same either way – only the split changes.
| Sale | Tax to add | Example at 18% GST |
|---|---|---|
| Customer in the same state as you (intra-state) | CGST + SGST | CGST 9% + SGST 9% |
| Customer in another state (inter-state) | IGST | IGST 18% |
For an intra-state sale, half the GST goes to the central government (CGST) and half to your state (SGST). For an inter-state sale, the full rate is charged as IGST. In Catalystk, choose the IGST tax instead of CGST + SGST on each item when the place of supply is another state.
Tips for correct GST invoices
- Enter the customer's GST number on every B2B invoice – they need it to claim input tax credit.
- Keep HSN/SAC codes on your products so every GST invoice picks them up automatically.
- Print original, duplicate, triplicate or quadruplicate copies, or print the GST invoice on your letterhead.
- Need an e-invoice (IRN) or e-way bill? Open the saved invoice and use the E-Invoice or E-Way Bill button.
Frequently asked questions
What is a GST invoice?
A GST invoice (tax invoice) is the bill a GST-registered business issues. It shows the GSTINs, HSN/SAC codes, taxable value and the GST charged on each item.
When do I charge CGST + SGST and when IGST?
Charge CGST + SGST for a sale within your state (intra-state) and IGST for a sale to another state (inter-state).
Where do I enter the customer's GST number?
In the client information of the invoice, in the GST Number field. It prints on the GST invoice.
Does the GST invoice show HSN/SAC codes?
Yes. Each item carries its HSN or SAC code on the invoice.
Can I print the invoice in duplicate or triplicate?
Yes. Catalystk prints original, duplicate, triplicate and quadruplicate copies, and can print on your letterhead.
Can I generate an e-invoice (IRN) for a GST invoice?
Yes. Open the saved invoice and click E-Invoice to get the IRN and signed QR code from the GST portal.
What is place of supply in a GST invoice?
The state where the goods or services are supplied. It decides whether you charge CGST + SGST (same state) or IGST (another state). Select it with the State Code.
Is GST billing free in Catalystk?
Yes. GST billing and GST invoices are free for lifetime.
What's next: see everything the lifetime free GST billing software does – payments, dues, e-invoice and e-way bill.
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