How to Set Up GST in Odoo 19: HSN, CGST, SGST, IGST and Returns

Short answer: in Odoo 19, the Indian localisation (Indian - Accounting) installs itself for a company based in India and brings the Indian chart of accounts, GST taxes and GST fiscal positions. Add your company’s state and GSTIN, tick Registered Under GST in Accounting ‣ Configuration ‣ Settings, put an HSN or SAC code and the intra-state GST tax on every product, and give each contact a GST treatment and GSTIN. Odoo then compares the place of supply with your state and applies CGST plus SGST, or IGST, by itself. Filing GSTR-1 and matching GSTR-2B from Odoo is Enterprise only.

This is the hands-on setup guide. For the general idea of how taxes and fiscal positions work together, start with my explainer on taxes and fiscal positions in Odoo.

Applies to

• Odoo version: Odoo 19. I also checked the Odoo 20 India documentation, which currently reads the same as the Odoo 19 page. The Odoo 20 code does change some screens, though: Registered Under GST becomes a Registration Type field (Regular or Composition), and there are separate charts of accounts for corporate and non-corporate entities. Check on a 20 database before following these steps there.
• Edition: Community and Enterprise for the chart of accounts, GST taxes, fiscal positions and HSN codes. GST return filing, GSTR-2B matching and the GSTR reports come from the Indian - Accounting Reports module, which is Enterprise only.
• Apps: Invoicing or Accounting. Sales and Purchase use the same taxes.

Before you start

1. The company has a full Indian address: street, city, State, six-digit PIN code and Country. Odoo builds the intra-state fiscal position from the company’s state, so this has to be right.
2. The Indian package is installed. In Accounting ‣ Configuration ‣ Settings, the Package under Fiscal Localization should be the Indian one. You can only switch package before any entry is posted.
3. You have your GSTIN and PAN, plus the HSN codes (goods) and SAC codes (services) for what you sell. GST rates come from government notifications, so confirm each rate with your tax adviser rather than trusting a default.
4. Composition dealers, read this first: the help text on Registered Under GST says to tick it if you have a GST number except under the composition scheme.

Step by step

1. Company details. Open Settings, scroll to Companies, click Update Info and fill in the address, PAN and GSTIN. If the first two digits of the GSTIN don’t match the state, Odoo shows a warning with an update it link. In Odoo’s state data, Punjab is 03 and Haryana is 06.
2. Switch GST on. In Accounting ‣ Configuration ‣ Settings, scroll to Indian Integration, tick Registered Under GST and check the GST Number. This activates the GST taxes, which are installed archived. Saving a valid GSTIN on the company also ticks the box for you.
3. Default taxes. At that moment Odoo 19 sets the company’s default sales and purchase taxes to the 5% GST taxes. If most of your catalogue uses another rate, change Default Taxes in the Taxes section of the same page, so new products start with the right tax.
4. HSN/SAC Validation. Still in Indian Integration, choose 4, 6 or 8 digits. Odoo labels the options by turnover; pick the one your adviser confirms. Invoice lines with a shorter or non-numeric code then raise a warning.
5. Learn the tax names. Open Accounting ‣ Configuration ‣ Taxes. Each intra-state rate is a group tax: 18% GST S (sales) is 9% SGST plus 9% CGST. Its inter-state twin, 18% IGST S, lists the inter-state fiscal position in its Fiscal Position field and the GST tax in Replaces. Purchase taxes end in P.
6. Products. On each product’s General Information tab, fill in HSN/SAC Code (below Product Category). Type a code or a few words and Odoo suggests matches from the GST portal’s HSN search. Set Sales Taxes to the intra-state GST tax, and on the Purchase tab set Purchase Taxes the same way. Never put IGST on a product: the fiscal position swaps it when needed.
7. Contacts. For each customer and vendor, set GST Treatment (for example Registered Business - Regular, Unregistered Business, Consumer or Overseas), the GSTIN and the State. Odoo fills PAN from the GSTIN. Leave Fiscal Position on the Sales & Purchase tab empty, because a fiscal position on the contact overrides Odoo’s place-of-supply logic.
8. Check the fiscal positions. Accounting ‣ Configuration ‣ Fiscal Positions should list Within your state (for example Within Punjab), Inter State, Special Economic Zone (SEZ), Export, two LUT (WOP) positions and two Reverse charge positions. Odoo detects the first four by itself; you choose the LUT and reverse charge ones by hand.
9. Reverse charge purchases. On a bill where you, the buyer, pay the GST, open the Other Info tab and choose Reverse charge Intra State or Reverse charge Inter State before adding lines. Odoo swaps in the matching GST RC or IGST RC taxes, which carry the Reverse charge flag used by the GST reports.
10. Returns (Enterprise only). On the GST portal, enable API access under My Profile ‣ Manage API Access. In Odoo, tick GST E-Filing & Matching, enter your GST Username and make sure the GSP field is set. On the Accounting dashboard, click Tax Returns on the Tax Returns journal and fill in Opening Date, Fiscal Year End and GSTIN Periodicity.
    • GSTR-1: open the period’s return and clear the validation checks (wrong tax for the state, missing or invalid HSN codes, missing e-invoices and others). Click Validate, then Submit and Push Data. After Check Status, click Mark as Filed. A filed return can’t be reset.
    • GSTR-2B: open the period, click Fetch E-Invoice and Validate, then Fetch GSTR-2B. Odoo matches the portal’s invoices with your bills. Correct any mismatched bills, use Re-Match, then Mark as Complete.
    • GSTR-3B: go to Accounting ‣ Reporting ‣ Tax Report and pick the GSTR-3B report in the report selector.

Worked example: a Punjab distributor selling in Punjab and Haryana

A hardware distributor in Ludhiana, Punjab, is registered under GST. Its company state is Punjab, so Odoo created Within Punjab and Inter State fiscal positions. Its brass door hinges have an 8-digit HSN code and 18% GST S as the sales tax. The 18% is for illustration only; use the rate notified for your own code.

Invoice	Customer	Place of supply	Fiscal position	Tax on ₹50,000
1	Registered retailer, Amritsar	Punjab	Within Punjab	CGST ₹4,500 + SGST ₹4,500
2	Registered dealer, Panchkula	Haryana	Inter State	IGST ₹9,000

• Invoice 1: the place of supply matches the company’s state, so the product’s 18% GST stays and splits into CGST and SGST. Total ₹59,000.
• Invoice 2: Haryana differs from Punjab, so Inter State replaces 18% GST S with 18% IGST S. The total is also ₹59,000; only the split changes.
• A different delivery address: if the Amritsar retailer asks for delivery to its own branch in Haryana, Odoo takes the place of supply from that delivery address and applies IGST. You can still change Place of supply on the draft if your adviser says the rule differs for that sale.
• Purchases: a bill from a Haryana supplier gets IGST, because on bills Odoo compares the vendor’s state with yours.

What you should see

• On a draft invoice: Place of supply and GST Treatment filled in, and the fiscal position on Other Info.
• In the invoice totals: CGST and SGST lines, or a single IGST line.
• On the PDF: an HSN/SAC column, an HSN Summary table split by SGST/UTGST, CGST, IGST and CESS, and the place of supply.
• In Enterprise: GSTR-1 (IN), GSTR-2B and GSTR-3B available in the Tax Report’s report selector.

Troubleshooting

IGST on a sale inside your own state, or CGST and SGST on an inter-state sale. Check the customer’s State, the invoice’s Place of supply, and that the contact has no fiscal position on its Sales & Purchase tab. Then check the company’s state: saving it updates the Indian fiscal positions.

No GST taxes to choose from. Registered Under GST isn’t ticked, so the GST taxes are still archived.

The HSN/SAC Code field is missing on products. Same cause: the field only shows for a company registered under GST.

A banner on the invoice about HSN/SAC digits. The code is missing, isn’t 4, 6 or 8 digits, or is shorter than your HSN/SAC Validation setting. Fix the product, then the line on the draft invoice.

“Invalid sequence as per GST rule 46(b)”. The invoice number is over 16 characters or uses special characters other than hyphen and slash. Shorten the sales journal’s sequence.

GSTR-1 flags “Invalid HSN Codes”. Codes for goods must not start with 99, and codes for services must.

Related setup

• How to set up taxes and fiscal positions in Odoo
• How to set up a chart of accounts in Odoo
• Customer invoicing in Odoo
• Odoo 20 in India: availability and GST
• Moving an Indian business onto Odoo, or fixing GST on a live database? See Odoo implementation.

Official references

• Odoo 19 documentation: India (fiscal localisation)
• Odoo 19 documentation: Fiscal localizations
• Odoo 19 documentation: Taxes
• Odoo 19 documentation: Fiscal positions
• Government of India: GST portal, for rates, HSN codes and filing rules

How this guide was checked: menu paths, field names and Enterprise-only status were checked against the Odoo 19 documentation and the Indian localisation code in Odoo 19 (the tax, fiscal position, company, contact and invoice logic) in October 2026. The worked example is illustrative and wasn’t run on a live database, so there are no screenshots; labels can vary slightly with your installed apps and language.