GST on construction is the goods and services tax levied on construction services, works contracts, and related materials in India. Every builder, contractor, sub-contractor, or developer whose annual turnover exceeds ₹20 lakhs must register on the GST portal and file monthly returns. For businesses in special category states, the threshold is ₹10 lakhs. Even if your turnover is below the limit, voluntary GST registration is advisable if your clients are GST-registered and need input tax credit from your invoices.

GST rates for construction depend on the type of project. Affordable housing projects attract 1% GST without ITC. Other residential projects attract 5% GST without ITC. Commercial construction and composite works contracts attract 12% with ITC. Works contracts for government projects are taxed at 12%, while other works contracts attract 18% GST. Choosing the wrong rate is one of the most common and costly errors — Tax Robo’s CAs verify the correct rate for every invoice before filing on the GST portal.

GSTR-1 is the outward supply return filed by the 11th of every month — you report all sales invoices and works contract details raised to clients during the previous month. GSTR-3B is the monthly summary return filed by the 20th — you report your GST liability, claim eligible input tax credits, and pay the net GST due to the government. Both returns must be filed every month without fail. Tax Robo prepares and files both GSTR-1 and GSTR-3B as part of every plan.

A GST on construction company in India must register on the GST portal if annual turnover crosses ₹20 lakhs. The process involves submitting PAN, Aadhaar, business address proof, and bank account details. Once approved, you receive a GSTIN and can begin issuing tax invoices to clients. Registration typically takes 7–10 working days. Tax Robo handles the complete GST registration process and can also take over your monthly filings immediately after registration is done.

GST on construction works contract is calculated on the total contract value — including both materials and labour in a composite contract. For works contracts to private clients, the rate is 18%. For works contracts to government bodies and local authorities, the rate is 12%. The applicable GST is calculated on the invoice value, collected from the client, and paid to the government via GSTR-3B after deducting eligible ITC. Tax Robo verifies the correct rate and calculates the net liability accurately before every filing.

The due dates for monthly GST return filing are the 11th of the month for GSTR-1 and the 20th of the month for GSTR-3B. For businesses under the QRMP scheme (turnover below ₹5 crore), GSTR-1 is filed quarterly and GSTR-3B is paid monthly using the challan. Missing the due date attracts a late fee of ₹50 per day (₹25 CGST + ₹25 SGST) plus 18% interest on unpaid GST. Tax Robo tracks all due dates and files your returns before the deadline every single month.

GST on real estate construction applies only to under-construction properties — when a buyer books a flat or commercial space before the completion certificate is issued. Affordable housing projects (value up to ₹45 lakhs, carpet area up to 60 sqm) attract 1% GST. Other residential projects attract 5% GST. Commercial properties attract 12% GST with ITC. Ready-to-move-in properties where the completion certificate has been issued before the sale are fully exempt from GST — no GST is applicable on such transactions.

Builders can claim GST input tax credit for construction materials and services only on commercial construction projects. For residential projects under the 1% and 5% scheme, ITC is blocked — it cannot be claimed as a condition of availing the lower GST rate. For commercial construction, ITC can be claimed on cement, steel, sand, electrical fittings, professional fees for architects and engineers, and sub-contractor services — provided the supplier is GST-registered and has filed their returns, and the invoices are visible in your GSTR-2B. Tax Robo reconciles GSTR-2B every month to ensure you claim every eligible credit.