📋 Taxes in India — GST Guide

GST Filing & Compliance — Complete Guide FY 2026-27

GST (Goods and Services Tax) replaced 17 indirect taxes in India on 1st July 2017. Every GST-registered person must file returns, maintain records, and claim ITC correctly — or face interest, penalties, and blocked credit. This guide uses official GST Portal data updated for FY 2026-27.

▶ Start: GST Registration — Who Must Register?

GST registration is mandatory once your aggregate turnover crosses the threshold. Source: gst.gov.in — Section 22 of CGST Act, 2017

📌 Registration Process: Apply on gst.gov.in → REG-01 form → Upload PAN, Aadhaar, address proof, bank details → Verification within 7 working days → GSTIN issued (15-digit number: 2-digit state code + 10-digit PAN + 3 digits). Voluntary registration is also allowed below threshold.

🔷 GST Returns — GSTR-1, 3B, 9 & 9C

The GST return ecosystem has multiple forms. Here are the key ones every registered taxpayer must know:

• 📋 GSTR-1 (Outward Supplies): Report all B2B and B2C sales invoices. Monthly filers → 11th of next month. Quarterly filers (QRMP scheme, turnover ≤ ₹5 Cr) → 13th of month after quarter. B2B invoices flow to buyer’s GSTR-2B for ITC claim.
• 📋 GSTR-3B (Summary Return + Tax Payment): Monthly self-assessed summary of sales, ITC, and net tax payable. Due: 20th of next month for large taxpayers; 22nd/24th for QRMP. Tax must be paid by due date to avoid interest @ 18% p.a.
• 📋 GSTR-2B (Auto-drafted ITC): System-generated monthly ITC statement — shows all invoices filed by your suppliers. Available by 14th of next month. Match GSTR-2B before claiming ITC in GSTR-3B.
• 📋 GSTR-9 (Annual Return): Consolidates all monthly/quarterly returns for the year. Mandatory for turnover >₹2 Cr. Due: 31st December of next financial year. Optional for ≤₹2 Cr.
• 📋 GSTR-9C (Reconciliation Statement): Certified reconciliation between GSTR-9 and audited financial statements. Mandatory for turnover >₹5 Cr — must be filed by a CA/CMA.

💡 Calculation Example — GSTR-3B Tax Payable:

🔷 Input Tax Credit (ITC) — Rules & Conditions

ITC is the GST paid on your purchases which can be set off against your output GST liability. Getting ITC wrong is the most common — and costly — GST mistake. Section 16 of CGST Act lists the conditions:

• ✅ Condition 1: You must have a valid tax invoice or debit note from the supplier
• ✅ Condition 2: You must have received the goods or services
• ✅ Condition 3: The supplier must have filed their GSTR-1 — the invoice must appear in your GSTR-2B
• ✅ Condition 4: You must have paid the tax amount to the supplier (within 180 days — or reverse ITC with interest)
• ✅ Condition 5: You must have filed your own GST return
• 🚫 Blocked Credits (Section 17(5)): ITC NOT available on — Motor vehicles (personal use), Food & beverages, Club memberships, Health insurance for employees, Construction of immovable property

💡 ITC Reversal Example — 180-Day Rule:

🔷 GST Compliance Calendar FY 2026-27

• 📅 11th every month: GSTR-1 (monthly filers — outward supply details)
• 📅 13th every month: GSTR-1 / IFF for QRMP quarterly filers
• 📅 14th every month: GSTR-2B auto-generated (view your ITC statement)
• 📅 20th every month: GSTR-3B + tax payment (large taxpayers, turnover >₹5 Cr)
• 📅 22nd/24th every month: GSTR-3B for QRMP monthly payment (22nd — Cat I states; 24th — Cat II states)
• 📅 25th every month: GST PMT-06 — quarterly QRMP tax payment for months 1 & 2 of quarter
• 📅 31st December 2026: GSTR-9 (Annual Return FY 2025-26) + GSTR-9C (Reconciliation)
• ⚠️ Late Fee: ₹50/day (₹25 CGST + ₹25 SGST) for GSTR-3B; ₹200/day for GSTR-9. Max late fee = 0.25% of turnover

🔷 E-Invoicing — Rules & Who Must Comply

E-invoicing means reporting B2B invoices to the Invoice Registration Portal (IRP) in real-time and getting an Invoice Reference Number (IRN) and QR code. Mandatory per GST Notification No. 10/2023.

• 📌 Applicability (from 1 Aug 2023): Mandatory for all B2B suppliers with aggregate turnover >₹5 Crore in any preceding FY
• 📌 Exempted: Banks, NBFCs, insurers, SEZ units, government departments, passenger transport services
• 📌 Process Flow: 1️⃣ Generate invoice in ERP/accounting software → 2️⃣ Upload JSON to IRP (einvoice1.gst.gov.in) → 3️⃣ IRP validates and generates IRN (64-character hash) → 4️⃣ IRP embeds QR code → 5️⃣ IRN auto-populates GSTR-1 (no manual entry needed)
• 📌 Cancellation: E-invoice can be cancelled within 24 hours of IRN generation only — after that, raise a credit note
• ⚠️ Penalty for non-compliance: Invoice without IRN = invalid invoice → buyer cannot claim ITC → ₹10,000 penalty per invoice

✅ End: GSTR-9 Annual Return — Complete Guide

• What is GSTR-9? Annual summary of all outward and inward supplies, ITC claimed, tax paid, and demand/refund — for the full financial year
• Mandatory: Turnover >₹2 Cr | Optional: ≤₹2 Cr (but advisable to file for record)
• GSTR-9C: Reconciliation of GSTR-9 with audited financials — mandatory for turnover >₹5 Cr; must be certified by CA/CMA
• 📅 Due Date: 31st December of the following FY (e.g., GSTR-9 for FY 2025-26 due by 31 Dec 2026)
• Common Errors to Avoid: ITC mismatch between GSTR-3B and GSTR-2A/2B; turnover mismatch with financials; unclaimed ITC from prior months not carried forward

💡 GSTR-9 Reconciliation Example: