evSuryam is built for Indian solar vendors, which means GST isn't an afterthought — it's wired through every quote, invoice, and purchase bill. Get your company state and your catalog's HSN codes right once, and the system computes the correct tax heads, tracks your Input Tax Credit, and hands your CA clean numbers at month-end. This page explains how each piece works.
Overview
Three pieces of data drive the entire GST engine: your registered state (from Settings), the customer's state (from their record), and the HSN/SAC code + rate on each catalog item. Everything else — which tax heads apply, how much, and how it rolls up into your returns — is derived from those three.
public/images/docs/gst-compliance.pngYour registered state is the foundationIf the state in Settings → Company Profile is wrong, every invoice picks the wrong tax heads. evSuryam derives your state code from your GSTIN — confirm it matches your registration before you raise a single invoice.
1. CGST+SGST vs IGST
Indian GST splits a sale into different tax heads depending on whether it crosses a state border. evSuryam decides this automatically by comparing the first two digits of your GSTIN (your state code) with the customer's state:
- Intra-state supply — customer is in the same state as you. The GST rate is split equally into Central GST (CGST) and State GST (SGST). A 12% line becomes 6% CGST + 6% SGST.
- Inter-state supply — customer is in a different state. The full rate applies as a single Integrated GST (IGST). A 12% line becomes 12% IGST.
You never choose between these manually — picking the customer (and their state) on the quote is enough. This is why capturing the customer's correct state matters as much as your own.
Place of supplyFor goods, the place of supply is normally where the goods are delivered. For a rooftop installation, that's the customer's site. If you install across state lines from where you're registered, expect IGST — and make sure the customer record reflects the site state.
2. HSN/SAC codes
Every catalog item carries an HSN code (for goods) or a SAC code (for services). These codes are mandatory on GST invoices above the prescribed turnover thresholds, and they determine the tax rate that applies to the line.
- Goods — panels, inverters, mounting structure, cables, and balance-of-system parts use HSN codes.
- Services — installation, commissioning, and annual maintenance use SAC codes.
Set the code once on the catalog item and it prints on every quote and invoice automatically, and rolls up correctly in your HSN-wise summary for returns. To add or edit codes, see the catalog section of Getting started.
3. Solar GST rates
Solar attracts concessional GST on most goods, with full rates on standalone services. The table below lists the codes you'll use most often. Rates and HSN classifications are notified by the GST Council and change periodically — treat this as a starting point and confirm the current rate with your CA before relying on it for filings.
| Item | Typical HSN / SAC | Type | Typical GST |
|---|---|---|---|
| Solar PV modules / panels | 8541 | Goods | 12% |
| Solar inverters | 8504 | Goods | 12% |
| Solar power generating system (kit) | 8541 / 8501 | Goods | 12% |
| Mounting structure (MMS) | 7308 | Goods | 18% |
| DC / AC cables & connectors | 8544 | Goods | 18% |
| Installation / commissioning service | 9954 (SAC) | Service | 18% |
| Annual maintenance (AMC) | 9987 (SAC) | Service | 18% |
Composite supply vs separate linesA turnkey rooftop contract can be treated as a composite supply of a solar power generating system, which the Council has clarified is taxed using a defined goods/service split. How you structure the lines affects the blended rate — decide your approach with your CA and keep your catalog consistent with it.
4. Input Tax Credit
The GST you pay on purchases — modules from your distributor, inverters, structure, even office overheads — is Input Tax Credit (ITC) you can set off against the GST you collect from customers. evSuryam captures this from your purchase bills.
- Log each supplier bill under Inventory → Purchases, entering the supplier's GSTIN, the line items, and the tax charged.
- evSuryam records the CGST/SGST/IGST you paid as available input credit.
- At return time, your output tax (collected on sales) is netted against your input tax (paid on purchases). You remit only the difference.
Accurate, complete purchase logging is what makes your ITC claim defensible — see Inventory & purchases for the full workflow.
ITC depends on your supplier filing tooYou can only claim ITC that appears in your auto-drafted GSTR-2B, which is populated from your suppliers' GSTR-1 filings. Log the bill in evSuryam for your records, but reconcile against GSTR-2B before claiming — a supplier who hasn't filed can block your credit.
5. GSTR-1 & GSTR-3B exports
At month-end, evSuryam rolls your invoices and purchases into the summaries your CA needs to file the two core returns:
- GSTR-1 — your outward supplies (sales). Exported invoice-wise and HSN-wise so the figures drop straight into the return.
- GSTR-3B — your summary return netting output tax against ITC, with reverse-charge liabilities broken out separately.
Go to Reports, choose the period, and download the GSTR-1 and GSTR-3B summaries. Hand them to your CA, or use them to cross-check what your accounting software generated. The reverse-charge figures are separated automatically — covered next.
6. Reverse charge & subsidies
Two situations need special handling, and evSuryam supports both:
- Reverse Charge Mechanism (RCM) — on certain supplies (notably some imported inverters), you as the recipient pay the GST instead of the supplier. Flag the catalog item as subject to reverse charge and the liability flows correctly into GSTR-3B. Full walkthrough: Reverse-charge on imported inverters.
- Government subsidies — under schemes like PM Surya Ghar, part of the customer's cost is borne by the government. Record it on the quote and track its disbursal as a tagged payment. See PM Surya Ghar subsidy walkthrough.
What's next
The GST engine only works if the data feeding it is clean. Nail your catalog HSN codes in Getting started, log every supplier bill in Inventory & purchases, and review how tax lands on documents in Quotations & invoices.