How CGST, SGST, and IGST Work on an Invoice
Place of supply chooses the tax. Same state as your organization uses CGST and SGST. A different state uses IGST. HSN or SAC sits on each line.
Step 1
Open a new invoice
Go to Invoices and click New invoice. Select the customer first. Invoism can fill place of supply from the customer billing address.
Step 2
Set place of supply
In Place of supply, search and select the state where the supply is consumed. Compare it with the state on your organization profile. Same state means an intrastate supply: GST is split into CGST and SGST. A different state means an interstate supply: GST is charged as IGST. The total GST rate is not doubled. An 18% supply is CGST 9% plus SGST 9%, or IGST 18%.
Step 3
Add HSN or SAC on each line
Add line items from products, or search an HSN code on the line. Goods use HSN. Services use SAC. The product HSN is reused when the product already has one. Confirm the tax rate on the line matches that code.
Step 4
Choose whether prices include GST
Use the tax-inclusive option when the unit price already contains GST. Leave it off when the price is before tax and GST should be added. Review CGST, SGST, or IGST totals before you save. This screen applies the rate and place of supply you enter. It is not a filing or legal opinion. Confirm unusual cases with your tax advisor.
Common questions
When does an invoice use CGST and SGST instead of IGST?
When place of supply is the same state as your organization, Invoism treats the supply as intrastate and splits GST into CGST and SGST. When place of supply is a different state, it uses IGST.
What is place of supply?
Place of supply is the state you select on the invoice for where the goods or services are supplied. It often starts from the customer billing address. It is compared with your organization state to choose the tax split.
Do I enter HSN or SAC?
Use HSN for goods and SAC for services. Put the code on the invoice line, or store it on the product so new lines pick it up.
Expected outcomes
- Place of supply is set on the invoice
- Line items have HSN or SAC and the correct GST split
Related tutorials
How to Generate an Invoice
Create a GST-ready invoice from customer and product line items with correct totals.
How to Add a Customer
Create a customer with a display name, phone, and billing address. Business customers can also store GSTIN and PAN for GST invoices.
How to Set Up Your Organization
Upload a logo and save legal name, GSTIN, PAN, phone, and address. Those details are the seller block on invoice and quotation PDFs.