GST on solar quotations: what to show and what to confirm

Which tax heads appear

The tax heads on a quotation depend on two places: the state your company is registered in and the state of the customer. When they are the same, the tax is shown as CGST and SGST. When they are different, it is shown as IGST.

The head changes how the tax is shown and shared, not how much of it there is. Special cases exist, such as union territories, so a quotation for an unusual location should be checked with a tax adviser.

What a quotation needs for GST

Before you send, make sure the quotation has the facts that the tax depends on.

• Your company's state and the customer's state, both on file.
• Your GSTIN, checked on the GST portal, because a number can pass the format check and still be wrong.
• A rate on each line that you have set and can explain, not a figure typed from memory.
• The tax shown on each line and in the totals, so the customer can see how the total was built.

Supply and installation on separate lines

Some quotations list the equipment and the installation as separate lines, each with its own rate. How the two are treated for tax can depend on how the contract is structured, so confirm the treatment with a tax adviser before you decide how to show them.

This guide does not state a rate or a treatment for either line. It only says that each line should carry the rate you have set, and that the customer should be able to see it.

What this guide does not decide

Rates, classification codes and the goods and services they apply to are set by official notification, and they change. Read the current notification on the official GST source rather than copying a figure from a guide, a calculator or last year's quotation.

Bharat Solar Venture shows GST on a quotation but does not issue GST invoices, record payments or file returns. Keep invoicing and filing in the tool you already use for them.

What to check before you send

Run the same short check on every quotation so the tax is never a surprise to the customer or to you.

• Both states are on file and compared.
• Each line carries a rate you set.
• An unusual location has been checked with a tax adviser.
• The document you are sending is a quotation, not a GST invoice.

Step by step

1. 1

   Put both states on file

   Record your company's state and the customer's state.

2. 2

   Check your GSTIN

   Check the number on the GST portal before you rely on it.

3. 3

   Set a rate on each line

   Take the rate from the official source and set it yourself on each line.

4. 4

   Show the split

   Show CGST and SGST for the same state, and IGST for different states.

5. 5

   Keep the invoice separate

   Issue the GST invoice later, from your accounting tool.

Common mistakes

• Copying a rate from memory

  Rates are set by official notification and change, so copying last year's figure can put a wrong rate on a quotation.

• Trusting a well-formed GSTIN

  A number that passes the format check can still be wrong, so check it on the GST portal.

• Leaving a state off

  The tax heads come from comparing the two states, so both must be on file.

• Assuming the head changes the amount

  CGST and SGST versus IGST changes how the tax is shown and shared, not how much of it there is.

• Sending a quotation as an invoice

  A quotation is an offer. Issue the GST invoice separately, from your accounting tool.

What to check before you send

• Your company's state and the customer's state are both on file
• The GSTIN has been checked on the GST portal
• Each line carries a rate you set from the official source
• CGST and SGST are shown for the same state, and IGST for different states
• An unusual location has been checked with a tax adviser
• The document is a quotation, not a GST invoice

Sources

• GST portal (home page), read 13 Oct 2026