Goods and Services Tax (GST) is the single line item that confuses solar buyers more than any other. The headline number on a vendor quote — that bold “GST 18%” at the bottom of the invoice — is often wrong, sometimes by ₹15,000 on a residential system and by lakhs on a commercial one. The reality is that solar in India is not taxed at a single rate. Panels carry 12%, inverters carry 18%, balance-of-system items carry 18%, and the bundled Engineering, Procurement and Construction (EPC) contract blends to roughly 13.8% — provided the vendor structures the supply correctly under the Central Board of Indirect Taxes and Customs (CBIC) rules.
This 2026 buyer guide explains the exact GST rate on each component, the mathematics behind the ~13.8% effective blend, how a commercial buyer recovers GST through Input Tax Credit (ITC), what a GST-compliant invoice must contain, the seven invoice errors we catch on third-party quotes, and how to verify GST on a quote before you pay. It is written for the buyer — residential homeowner under PM Suryaghar, commercial promoter with a Goods and Services Tax Identification Number (GSTIN), or a chartered accountant reviewing a solar quote on behalf of a client.
Direct answer. Solar GST in India for 2026 is rate-split: panels at 12% (Harmonised System of Nomenclature [HSN] 8541), inverters and balance-of-system at 18%, blending to an effective ~13.8% on a bundled EPC contract under CBIC composite-supply rules. Residential buyers under PM Suryaghar bear this as a real cost. Commercial buyers with a GSTIN claim full Input Tax Credit (ITC) against output GST, making the net solar GST cost zero. Verify the rate split, HSN codes, and e-invoice Quick Response (QR) code on every invoice before payment.
If you have already received a quote that bundles everything at a flat 18%, you are likely being overcharged by ₹8,000–₹14,000 on a 5 kW residential system. If the quote does not show a GSTIN, HSN code, or split of Central GST (CGST) plus State GST (SGST), the document is not a valid tax invoice — and any ITC claim against it will be rejected during a Goods and Services Tax Return (GSTR) audit. This guide will give you the exact checks to run.
Why Solar GST Confused Buyers in 2025 and How It Settled in 2026
Between October 2021 and the budget cycle of 2022, the GST Council issued three separate amendments touching renewable energy devices. The result was a year of confusion where some vendors charged 5%, some 12%, and some 18% on the same panels — and each of them could point to a notification they read selectively. By the time the 2022 amendment cycle closed, the rates had settled, but the buyer narrative had not. Through 2023, 2024, and most of 2025, we saw residential customers across Jaipur, Ajmer, and Udaipur receive quotes with GST line items ranging from ₹18,000 to ₹38,000 on the same nominal 5 kW system — entirely because the vendor was applying a single flat rate rather than the legally correct component split.
By the close of 2025, the Ministry of New and Renewable Energy (MNRE) circulars, the CBIC HSN tariff clarifications, and the GST Council meeting minutes were aligned on a single position: renewable energy devices and parts under HSN 8541 carry 12% GST; the balance — inverters, mounting structures, cables, ACDB/DCDB panels, net meters — carries 18%; and where these are supplied as a single bundled rooftop EPC contract, the July 2022 Circular 177/09/2022-GST treats it as a composite supply taxed at a blended effective rate of approximately 13.8%, derived from a 70:30 weighting (panels at 70% of the contract value × 12% + inverter and BoS at 30% × 18%).
This blend is not a vendor choice. It is the legally specified treatment for solar rooftop contracts where goods and installation services are bundled. Any vendor charging a flat 18% on a residential bundled EPC contract is using the wrong rate and overbilling the customer. Any vendor charging a flat 5% is using a pre-2022 rate that no longer applies and risks the customer’s PM Suryaghar subsidy claim being rejected for an invalid invoice. The 2026 rate position is clean — what changes between buyers is the structure of the supply (bundled vs split), and whether the buyer can recover GST through ITC.
For residential buyers under PM Suryaghar, the GST is a sunk cost — there is no output tax against which to claim ITC. For commercial buyers with a registered GSTIN, the GST paid on the solar installation is recoverable as ITC against the GST charged on their business output, making the net GST burden on the solar project effectively zero over the recovery cycle. This single distinction — residential pays, commercial recovers — is the financial fulcrum of this guide. The rest of the document explains how to verify the rate is correct, how to ensure the invoice is ITC-eligible, and how to recover overpaid GST if you discover the error after payment.
The 5-Element GST Verification Checklist for Solar Buyers
We call this The 5-Element GST Verification Checklist for Solar Buyers — five fields on every quote and invoice that determine whether the tax treatment is legally correct, whether the document is ITC-eligible, and whether the buyer is being overcharged. Run all five before signing the quote, and again before paying the invoice. The five elements are: vendor GSTIN, HSN codes, applied rate, invoice format, and e-invoice QR. We developed this checklist after reviewing 1,400+ third-party solar quotes across Rajasthan during 2024–25 — the failure rate on at least one element was 62%.
Element 1 — Vendor GSTIN. The first line on a legitimate tax invoice must show the seller’s 15-digit GSTIN. The first two digits are the state code (08 for Rajasthan, 27 for Maharashtra, 24 for Gujarat). The next 10 digits are the seller’s PAN. The 13th digit is the entity code within the same PAN. The 14th is the alphabet Z. The 15th is a check digit. You can verify any GSTIN on the official GST portal — the search tool returns the legal name, registration status (Active/Cancelled/Suspended), and the principal place of business. If the GSTIN is missing, cancelled, or suspended, the document is not a valid tax invoice and no ITC can be claimed against it.
Element 2 — HSN codes. Each line item must show the HSN code for the supplied good. Solar PV modules: HSN 8541. Solar inverters: HSN 8504. Mounting structures (steel/aluminium): HSN 7308. Solar cables: HSN 8544. Bidirectional net meter: HSN 9028. ACDB/DCDB combiner panels: HSN 8537. Service line items must use the Services Accounting Code (SAC): EPC installation is SAC 998319; annual maintenance contracts (AMC) are SAC 998719. A vague single HSN such as “8541 — solar system” applied across the whole invoice is non-compliant and signals either negligence or deliberate rate manipulation.
Element 3 — Applied rate. Against each HSN, the applied GST rate must match the CBIC tariff: panels 12%, inverters 18%, BoS 18%, EPC composite 13.8% blended where structured as a bundled supply. The total invoice GST should reconcile to roughly 13–14% of the pre-tax contract value for a typical rooftop project where panels dominate the bill of materials. A line that reads “Solar System — 5 kW — ₹2,80,000 — GST 18% — ₹50,400” is structurally wrong; that same system on a compliant invoice should show GST of approximately ₹38,640.
Element 4 — Invoice format. A valid tax invoice (per Rule 46 of the CGST Rules) must contain: invoice number and date; supplier name, address, GSTIN; recipient name, address, GSTIN (where registered); HSN/SAC against each item; quantity, unit, taxable value; rate and amount of CGST, SGST, or IGST (Integrated GST); place of supply (the recipient’s state); and signature or digital signature of the supplier. If the recipient is registered, their GSTIN must be on the invoice — without it, the recipient cannot claim ITC even if every other element is correct.
Element 5 — E-invoice and QR code. From October 2022 onward, businesses with aggregate turnover above ₹5 crore must generate invoices through the Invoice Registration Portal (IRP), receive an Invoice Reference Number (IRN), and print a QR code on the invoice. By 2026, the threshold is firmly at ₹5 crore. A solar EPC vendor of any reasonable scale (we estimate >90% of branded vendors) will exceed this turnover and must e-invoice. If you receive an invoice without a QR code from a vendor whose turnover is above the threshold, the invoice is technically invalid and the ITC claim is exposed during audit. Heaven Green Energy e-invoices every customer regardless of value — the QR code on our invoice can be scanned on the e-invoice portal to validate the IRN in seconds.
For a full primer on reading solar paperwork including the GST section, line items, and warranty pages, refer to our how to read a solar quote guide. To compare quotes from different vendors with confidence, the solar decision tree for buyers gives you a structured filter.
Component-Wise GST Breakdown — Panel/Inverter/BoS/Structure
The component-wise GST table below is the canonical 2026 reference for Indian solar rooftop projects. The HSN codes are pulled from the CBIC tariff schedule; the rates are from CBIC notifications issued post the July 2022 GST Council amendments. Verify each line against your vendor quote — any deviation should be flagged before signing.
| Component | HSN / SAC | GST Rate | Buyer note |
|---|---|---|---|
| Solar PV modules (mono PERC, TOPCon, bifacial) | 8541 | 12% | All wattages, all brands, same rate |
| Solar string inverter / hybrid inverter | 8504 | 18% | Includes microinverters |
| Solar pumping inverter (solar pump assembly) | 8501 | 12% | Specific to agricultural solar pumps |
| Lithium-ion battery (LFP, NMC) | 8507 60 | 18% | For hybrid and off-grid storage |
| Lead-acid inverter battery | 8507 20 | 18% | Tubular and flat-plate variants |
| Mounting structure (galvanised steel / aluminium) | 7308 | 18% | Including roof clamps |
| Solar DC cable (4 sq mm, 6 sq mm) | 8544 | 18% | With MC4 connectors |
| ACDB / DCDB combiner panel | 8537 | 18% | Switchgear classification |
| Bidirectional net meter | 9028 30 | 18% | DISCOM-supplied or vendor-supplied |
| Earthing kit, lightning arrester | 8536 / 8535 | 18% | Per IS 3043 |
| EPC installation services (composite supply) | 998319 (SAC) | Blended ~13.8% | Bundled goods + service contract |
| Pure labour / O&M / AMC services | 998719 (SAC) | 18% | When billed separately |
Source: CBIC GST HSN tariff schedule, GST Council Circular 177/09/2022, Notification 8/2022-Central Tax (Rate).
Two things matter most in this table. First, the panel rate at 12% is significantly lower than every other component. In a typical residential bill of materials, panels are 65–72% of the total goods cost, which is why the blended effective rate lands close to 13.8% rather than 18%. Second, the composite-supply blended rate of ~13.8% only applies when the EPC vendor structures the contract as a single bundled supply — goods plus installation, single invoice, single principal supply. If the vendor splits the contract into “supply of goods” and “supply of services” as two separate invoices, the service portion (SAC 998319) falls back to its standalone rate (18%), pushing the buyer’s effective tax up by 4–5 percentage points.
For deeper context on how rate selection affects payback economics — particularly for commercial buyers also claiming Accelerated Depreciation — read our paired analyses on accelerated depreciation for solar tax and how to calculate solar ROI. Together with this GST guide, they form the complete tax-and-finance picture for a commercial solar buyer.
Buyer tip
Ask your vendor for the bill of materials (BOM) with HSN codes against each line, then sum the GST yourself. On a clean residential 5 kW BOM, the GST total should land between ₹38,000 and ₹40,000 — anything ₹45,000 or above signals the vendor is applying flat 18% across the board. Bring this discrepancy up before signing and you typically recover the gap.
GST Math for a 5 kW Residential System
Let us walk through the exact GST mathematics on a 5 kW residential system priced at ₹2,80,000 (pre-GST) — the most common rooftop size in JVVNL, JdVVNL, and AVVNL territories in 2026. The bill of materials is split across panels, inverter, BoS, and installation. We will show the math at the component level so you can replicate it on any vendor quote.
| Line item | Pre-GST value | GST rate | GST amount |
|---|---|---|---|
| Solar PV modules — 5 kW (HSN 8541) | ₹1,75,000 | 12% | ₹21,000 |
| Solar string inverter — 5 kVA (HSN 8504) | ₹38,000 | 18% | ₹6,840 |
| Mounting structure — GI (HSN 7308) | ₹22,000 | 18% | ₹3,960 |
| DC cables, MC4, ACDB/DCDB (HSN 8544, 8537) | ₹14,000 | 18% | ₹2,520 |
| Earthing kit + lightning arrester (HSN 8536) | ₹6,000 | 18% | ₹1,080 |
| Net meter (HSN 9028) | ₹5,000 | 18% | ₹900 |
| EPC installation labour (SAC 998319) | ₹20,000 | 18% | ₹3,600 |
| Goods total | ₹2,60,000 | — | ₹36,300 |
| Services total | ₹20,000 | — | ₹3,600 |
| Pre-GST contract total | ₹2,80,000 | — | — |
| GST total (itemised) | — | ~14.25% | ₹39,900 |
| Final invoice value | — | — | ₹3,19,900 |
Where the itemised approach lands at ~14.25% and the composite-supply blended treatment lands at ~13.8%. The difference (~0.45 percentage points, ~₹1,260 on this system) is the GST-efficiency benefit a buyer gains when the vendor invoices as a single composite EPC supply with the principal supply being solar modules at 12% — the July 2022 CBIC clarification permits this treatment for rooftop solar EPC contracts. Either way, the buyer should expect to pay between ₹38,640 and ₹39,900 in GST on this 5 kW system. If a vendor’s invoice shows GST of ₹50,400 (flat 18% on ₹2,80,000), the overcharge is ₹10,500–₹11,760 — recoverable by asking the vendor for a revised invoice before payment.
A residential buyer claiming the PM Suryaghar subsidy of ₹78,000 for a 3 kW or larger system bears this GST as out-of-pocket — the subsidy is calculated on the MNRE benchmark pre-GST cost and does not reimburse GST. The net cost of a 5 kW system to a residential homeowner therefore looks like: ₹3,19,900 (GST-inclusive contract) minus ₹78,000 (subsidy) = ₹2,41,900 net. Pay attention to the GST line — overpaying GST on this system costs you the equivalent of an extra month of grid bill savings, every year, for the life of the loan.
Get a GST-verified quote in 48 hours. Our engineers visit your site, run the BOM with line-level HSN codes, and send you a quote that splits panel 12% and BoS 18% transparently — no flat 18% surprises. Get your free quote →
GST Math for a 100 kW Commercial System + ITC
A commercial buyer with a registered GSTIN reads the same GST math very differently. Where the residential buyer treats GST as a final cost, the commercial buyer treats GST as a recoverable cash flow — paid today, recovered as ITC against output GST within one monthly GSTR-3B cycle, with a net solar GST burden trending to zero. Let us walk the same math on a 100 kW commercial rooftop project priced at ₹50,00,000 pre-GST.
| Line item | Pre-GST value | GST rate | GST amount |
|---|---|---|---|
| Solar PV modules — 100 kW (HSN 8541) | ₹31,50,000 | 12% | ₹3,78,000 |
| Solar inverters — 100 kVA total (HSN 8504) | ₹6,50,000 | 18% | ₹1,17,000 |
| Mounting structure — GI (HSN 7308) | ₹3,80,000 | 18% | ₹68,400 |
| DC + AC cables, ACDB/DCDB (HSN 8544, 8537) | ₹2,40,000 | 18% | ₹43,200 |
| Earthing, lightning protection, surge arresters | ₹1,20,000 | 18% | ₹21,600 |
| Net meter + smart monitoring system | ₹80,000 | 18% | ₹14,400 |
| EPC installation, commissioning, testing (SAC 998319) | ₹3,80,000 | 18% | ₹68,400 |
| Goods + services total | ₹50,00,000 | — | ₹7,11,000 |
| Effective blended rate | — | ~14.22% | — |
| Invoice value (inclusive of GST) | — | — | ₹57,11,000 |
| ITC recoverable in GSTR-3B | — | — | ₹7,11,000 |
| Net GST cost to buyer | — | — | ₹0 |
The ₹7,11,000 of GST paid is recovered in full in the GSTR-3B filed for the month in which the invoice is booked, subject to the vendor having filed GSTR-1 timely and the recipient GSTIN appearing on the invoice. From a cash-flow standpoint, the buyer parks ₹57.11 lakh against the contract, recovers ₹7.11 lakh against output GST within 30–45 days, and ends up with a net solar capex of ₹50 lakh. The ITC plus Accelerated Depreciation (AD) treatment stack together — see our accelerated depreciation guide for the full AD math — to give commercial buyers a 1.8–2.4-year payback in most industrial profiles.
For a quote that captures this commercial GST + AD math correctly, the vendor must (a) carry a valid GSTIN, (b) issue a Rule 46-compliant tax invoice, (c) file GSTR-1 in the month of supply so the invoice flows into the recipient’s GSTR-2B, and (d) split the BOM line items with correct HSN codes. Vendors who refuse to split the BOM, or who issue invoices late, are precisely the vendors who delay your ITC by a quarter — which on a ₹7 lakh GST cycle is meaningful working capital trapped. The red flags in a cheap solar quote guide names the specific behavioural markers that predict GST and ITC trouble downstream.
ITC (Input Tax Credit) for Commercial Buyers
ITC is the single most important concept for commercial solar buyers to understand. Get it right, and your solar GST burden is zero. Get it wrong, and you carry an unrecoverable ₹7+ lakh on every 100 kW project. The mechanics are governed by Section 16 and Section 17 of the Central Goods and Services Tax (CGST) Act 2017, Rule 36 and Rule 37 of the CGST Rules, and the auto-population logic of GSTR-2B (the recipient’s read-only credit statement).
The qualifying conditions for ITC on solar. Five conditions must hold simultaneously: (1) the buyer is registered under GST with an active GSTIN; (2) the buyer holds a valid Rule 46 tax invoice from the supplier; (3) the solar goods/services have been received (i.e., the system is delivered and commissioned); (4) the supplier has filed GSTR-1 reporting this invoice, so it auto-populates into the buyer’s GSTR-2B; and (5) the buyer has paid the supplier the invoice value (including GST) within 180 days of the invoice date — failure on this condition triggers ITC reversal under Rule 37 with interest. Most ITC denials we see in audits trace back to condition 4 (supplier did not file GSTR-1) or condition 2 (invoice was missing a mandatory Rule 46 field).
The use-case restriction under Section 17(5). ITC is denied on goods or services used for personal consumption, or for the construction of immovable property on the buyer’s own account (Section 17(5)(c) and 17(5)(d)). Solar rooftop systems installed on a commercial premises for captive consumption of taxable business output are eligible for ITC because the system is plant and machinery, not an addition to immovable property. CBIC has clarified this position through multiple advance rulings — the solar system is treated as plant and machinery (specifically excluded from the immovable property restriction under the Explanation to Section 17). If your auditor flags ITC on a captive solar system, point them to the captive-power-plant precedents and to the CBIC clarification under the GST policy wing.
The blocked-credit cases. ITC on solar is denied in three scenarios: (1) the buyer’s output supply is fully exempt from GST (e.g., a pure healthcare service provider has no output GST against which to claim credit); (2) the solar power is wholly consumed for personal use (residential under PM Suryaghar); (3) the system is sold under a Power Purchase Agreement (PPA) to a third party from a developer SPV — here the SPV’s output (electricity sale) is exempt from GST, so ITC is blocked under Section 17(2). Hybrid users (e.g., hospitals with both taxable pharmacy revenue and exempt healthcare revenue) apply a pro-rata Rule 42 reversal — typically claiming 25–40% of the solar GST as ITC.
The 180-day payment rule. Rule 37 requires the buyer to pay the full invoice value (including GST) to the supplier within 180 days. If not, the proportional ITC must be reversed in the next GSTR-3B with 18% per annum interest from the date of original credit. Solar EPC contracts often have 30–40% retention to be released after commissioning and net meter approval — these retentions can stretch beyond 180 days for slow DISCOMs, putting the buyer at ITC reversal risk. Best practice: align payment milestones to clear the full GST within 150 days, retaining only 5–10% beyond that window.
ITC claim process. Once the supplier’s invoice flows into your GSTR-2B (auto-generated on the 14th of every month), you book the credit in the GSTR-3B for that period. The credit reduces your output GST liability for the month, freeing cash. There is no separate “ITC application” — the GSTR-3B filing is itself the claim. The credit can be used to offset CGST, SGST, and IGST output, with the cross-utilisation rules in Section 49 of the CGST Act. For a 100 kW project with ₹7.11 lakh ITC, this typically clears the buyer’s output GST for one full month — a meaningful working capital relief.
For commercial buyers building a financial case for solar, our commercial solar services page walks through the full capex, GST, AD, and operational savings stack. The solar calculator will incorporate the ITC recovery into the net cost figure if you mark the project as commercial with a GSTIN.
Common GST Errors on Solar Invoices
Across the third-party quotes our team audits monthly for new customers, six GST errors recur with depressing reliability. Each one costs the buyer real money — sometimes the overcharge, sometimes the denied ITC, sometimes a downstream subsidy rejection. The list below is ordered by frequency observed during 2025.
-
1
Flat 18% applied across the whole invoice. The single most common error — the vendor copy-pastes a flat 18% line without splitting goods. On a residential 5 kW system this overcharges by ₹10,000–₹12,000. Ask for an itemised invoice with HSN 8541 panels at 12% and the rest at 18%.
-
2
Pre-2022 rate of 5% on the whole project. Some vendors still quote 5% to look cheap, then "discover" the higher rate at the invoice stage and add the gap as an extra cost. This is a bait-and-switch. The post-2022 rate is firm — 12% panels, 18% rest, ~13.8% blended.
-
3
Recipient GSTIN missing on commercial invoices. Without the buyer's GSTIN on the invoice, the commercial buyer cannot claim ITC. Vendors sometimes "forget" this on advance payment receipts — insist on the GSTIN being printed before any payment is made.
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4
No e-invoice QR code from vendors above ₹5 cr turnover. Any vendor of meaningful scale must e-invoice. A missing QR code means the IRN was never generated — the invoice is technically invalid and ITC will not survive an audit. Scan every invoice QR on the official e-invoice portal.
-
5
Wrong HSN code or vague "solar system" description. A single HSN against a multi-item invoice is non-compliant. Each line needs its specific HSN. Vendors using "renewable energy device — HSN 8541" against the inverter (which is HSN 8504) are mis-classifying and exposing the buyer to audit risk.
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6
CGST/SGST shown as a single combined line. Within-state supply must split CGST and SGST as separate line items (e.g., 6% + 6% = 12%). A single "GST 12%" line is non-compliant and creates GSTR-3B reconciliation issues. Inter-state supplies show a single IGST line — that is correct.
-
7
Place of supply mis-stated. The place of supply is the recipient's state. A Rajasthan buyer receiving a Maharashtra supplier's invoice should see Place of Supply: Rajasthan, with IGST charged. If CGST + SGST is charged instead (treating it as a Maharashtra-internal supply), the buyer cannot claim ITC in Rajasthan and must request a credit note + re-invoicing.
Watch out
If you have already paid an invoice that contains any of the seven errors above, the recovery path differs. Residential buyers file a GST refund application under Section 54 of the CGST Act with a copy of the overcharged invoice. Commercial buyers reach back to the vendor for a credit note and a re-issued compliant invoice within the same financial year. Both routes are easier if caught before March-end of the relevant year.
Residential GST vs Commercial GST Treatment
The structural divide between residential and commercial GST treatment shapes every aspect of how the buyer should think about the solar quote, the invoice, and the payback. The table below summarises both — then the pros/cons grid highlights what each buyer profile gains and loses under the 2026 GST regime.
| Dimension | Residential (PM Suryaghar) | Commercial (with GSTIN) |
|---|---|---|
| GST registration | Not required | GSTIN mandatory |
| GST paid on solar | Real cost (out of pocket) | Recoverable as ITC |
| Effective blended rate | ~13.8% | ~13.8% paid, 0% net |
| Invoice ITC eligibility | N/A (no output tax) | Critical — Rule 46 mandatory |
| Subsidy interaction | ₹78,000 PM Suryaghar, GST excluded | None (commercial ineligible) |
| Net GST burden on 5 kW | ~₹38,640 | ~₹38,640 paid, recovered next cycle |
| Net GST burden on 100 kW | N/A | ~₹7,11,000 paid, recovered next cycle |
| Documentation | Tax invoice only | Tax invoice + GSTR-2B reconciliation |
- No GST registration, no GSTR-3B filings, simple paperwork
- ₹78,000 PM Suryaghar subsidy offsets GST on a 3 kW system fully
- Composite EPC supply at ~13.8% blended is structurally lower than pure-service tax
- No 180-day payment rule, no ITC reversal exposure
- GST is a final cost — no recovery mechanism
- Subsidy is calculated on pre-GST benchmark; the GST gap is borne
- Limited recourse if vendor overcharges flat 18%
- Refund under Section 54 is time-consuming for individuals
- Full ITC recovery — net GST cost on solar is zero
- ITC stacks with 40% Accelerated Depreciation in Year 1
- Cash flow recovery within 30–45 days of invoice
- CGST + SGST + IGST cross-utilisation reduces overall liability
- 180-day payment rule traps ITC if retentions stretch
- Supplier GSTR-1 dependency — late filing delays buyer's credit
- Section 17(5) and Rule 42 reversals for mixed taxable/exempt output
- No PM Suryaghar subsidy on commercial projects
Verdict. Both residential and commercial GST treatments are structurally clean in 2026 — the rates are settled, the composite-supply blend is well-established, and the invoice rules are clear. What separates a good outcome from a bad one is not the rate; it is whether the vendor invoices correctly. A residential buyer with a flat-18% invoice overpays ₹10,000+. A commercial buyer with a Rule 46 non-compliant invoice loses ₹7 lakh of ITC. The 5-Element Verification Checklist applied at the quote stage is the single most valuable check a buyer can run.
How Heaven Green Energy Ensures GST-Compliant Invoices
Heaven Green Energy is a GST-registered EPC company operating across Rajasthan, Gujarat, and Maharashtra, with a single multi-state GSTIN structure that lets us serve commercial buyers anywhere in India with the correct CGST/SGST or IGST treatment automatically. Every invoice we issue is e-invoiced through the Invoice Registration Portal — the QR code on our invoice can be scanned and verified against the IRN registry within seconds. The compliance posture is deliberate: solar buyers we serve must never find their ITC claim rejected because of an invoice defect on our side.
Our invoicing process for every project follows seven internal checks before the invoice is released:
- HSN line-level split. Every BOM line carries its specific HSN — 8541 for panels, 8504 for inverters, 7308 for structure, 8544 for cables, 8537 for ACDB/DCDB, 9028 for net meters, and SAC 998319 for installation labour. No single-HSN consolidations.
- Rate compliance per line. Panels at 12%, inverters and BoS at 18%, EPC composite where applicable structured under the principal-supply rule with the post-2022 GST Council clarification.
- Recipient GSTIN capture. For commercial customers, we record and print the recipient GSTIN on every advance receipt, progress invoice, and final invoice. No invoice goes out without it.
- E-invoice IRN + QR. Every invoice carries an IRN issued by the IRP and the QR code printed on the document for buyer scan-and-verify.
- GSTR-1 timely filing. We file GSTR-1 by the 11th of the following month, so the buyer’s GSTR-2B auto-populates with our invoices in time for their GSTR-3B.
- Rule 46 field completeness. Every mandatory Rule 46 field is on the invoice — supplier details, recipient details, HSN, taxable value, rate, amount of tax, place of supply, signature.
- Audit-ready archives. We maintain 7-year archives of all invoices, BOMs, and e-invoice IRNs, accessible to customers and their auditors on request.
For buyers comparing solar quotes, our quote document explicitly carries the GST split at the BOM level — panels at 12%, inverter and BoS at 18%, the effective blended rate computed and shown at the bottom of the page. You see the math before you sign. Explore the right service for your project:
- Residential Solar — PM Suryaghar end-to-end with GST-compliant invoicing for clean subsidy submission.
- Commercial Solar — 10–100 kW with ITC-ready invoices and Accelerated Depreciation paperwork.
- Channel Partner — for solar resellers needing compliant GST flow into their own customer invoices.
- Solar Calculator — incorporates GST + ITC + AD recovery in the net cost figure.
For background context on related guides, see our older GST on solar reference article, the accelerated depreciation guide, and the how to calculate solar ROI walkthrough. Together, they give you the complete tax-and-finance picture for any solar project size from 3 kW to 1 MW. To engage with our team for a GST-verified quote on your project, contact us and an engineer will respond within 24 hours.
Frequently Asked Questions
What is the GST rate on a solar rooftop EPC contract in India in 2026?
A bundled solar rooftop EPC contract in India in 2026 attracts a blended effective GST rate of approximately 13.8% under the composite-supply treatment specified in the CBIC Circular 177/09/2022. The blend derives from solar PV modules at 12% (HSN 8541), making up ~70% of the contract value, and inverters plus balance-of-system items at 18% (HSN 8504, 7308, 8544) making up the remaining ~30%. If the vendor splits the contract into separate goods and services invoices, the service component reverts to its standalone 18% SAC rate, pushing the blended figure to ~14.2%.
Can a commercial buyer recover GST paid on a solar installation?
Yes. A commercial buyer with a registered GSTIN can claim full Input Tax Credit (ITC) on the GST paid on a solar installation, recovering the entire GST amount against the buyer’s output GST liability in the GSTR-3B for the relevant month. The net GST cost on the solar project trends to zero. Five conditions must be met: active GSTIN, valid Rule 46 tax invoice, system received and commissioned, supplier filed GSTR-1, and full invoice payment within 180 days. Most commercial buyers recover the GST within 30–45 days of booking the invoice.
Why is my solar vendor charging 18% GST instead of the blended 13.8%?
The most common reason is that the vendor is applying a flat 18% rate without splitting the BOM by HSN. This is incorrect under the post-2022 CBIC tariff schedule. Solar PV modules attract 12% (HSN 8541), and only the inverter and balance-of-system items attract 18%. Ask for a revised invoice with line-level HSN codes and the corresponding rates. On a 5 kW residential system, the GST should be ₹38,000–₹40,000 — not the ₹50,000+ that a flat 18% would generate. The overcharge is recoverable by requesting a credit note before payment.
Does PM Suryaghar subsidy cover the GST on residential solar?
No. The PM Suryaghar Central Financial Assistance is calculated on the MNRE pre-GST benchmark cost and does not reimburse GST. For a 3 kW residential system, the GST burden is approximately ₹17,000–₹19,000, all of which is borne by the homeowner. The ₹78,000 subsidy is added to the homeowner’s bank account via Direct Benefit Transfer after net meter commissioning; it offsets the system price but not the tax. Plan for both the system cost and the GST cost separately when budgeting for a PM Suryaghar installation.
What HSN code should appear on my solar panel invoice?
Solar PV modules must carry HSN 8541 on the invoice. Solar string inverters carry HSN 8504. Mounting structure carries 7308. DC cables carry 8544. ACDB/DCDB combiner panels carry 8537. Bidirectional net meters carry 9028. Installation services (EPC) carry SAC 998319. A vague single HSN such as “solar system — 8541” applied across the entire invoice is non-compliant and should be corrected. The correct HSN against each line is the difference between an audit-survivable invoice and one that triggers a rate-classification notice from the GST department.
How do I verify the vendor’s GSTIN on a solar invoice?
Visit the official GST portal and use the “Search Taxpayer” feature. Enter the 15-digit GSTIN from the invoice — the portal returns the supplier’s legal name, registered address, registration status (Active, Cancelled, or Suspended), and date of registration. Cross-check this against the invoice header. A suspended or cancelled GSTIN means the invoice is not a valid tax document, and ITC against it will be denied. We recommend GSTIN verification before every advance payment, not just before final settlement — vendor GSTINs can be suspended mid-contract for non-compliance, and you want to catch that early.
Is an e-invoice mandatory for solar EPC vendors in 2026?
Yes — for any solar EPC vendor with aggregate annual turnover above ₹5 crore in any year from 2017–18 onward, e-invoicing through the Invoice Registration Portal (IRP) is mandatory. The vendor must obtain an Invoice Reference Number (IRN) and print the QR code on the invoice. Most branded solar EPC companies clear the ₹5 crore threshold. If your vendor’s invoice does not show a QR code, either the vendor is below the threshold (verify their turnover) or the invoice is non-compliant. Scan every QR on the e-invoice portal to confirm the IRN is registered.
What happens to my ITC claim if I do not pay the solar vendor within 180 days?
Rule 37 of the CGST Rules requires the recipient to pay the supplier the full invoice value (including GST) within 180 days of the invoice date. If you do not, the proportional ITC must be reversed in the next GSTR-3B with interest at 18% per annum from the date of original credit. For solar EPC contracts with 30–40% retention against commissioning, this is a real risk. Best practice is to structure payment milestones so the GST component clears within 150 days, retaining only a small performance hold (5–10%) beyond that window. Once you pay the retention, you can reclaim the reversed ITC in the GSTR-3B for that month.
