The Two Returns Every GST Taxpayer Must File
The original GST design envisioned GSTR-1 (outward), GSTR-2 (inward), and GSTR-3 (matching) — but GSTR-2 and GSTR-3 were never implemented. The current system relies on two returns:
GSTR-1 — Outward Supply Details (Section 37)
Report ALL outward supplies (sales) made during the period — B2B (with buyer GSTIN), B2C (without GSTIN), exports, advances received, credit/debit notes. This data flows to your buyer's GSTR-2A/2B, enabling them to claim ITC.
GSTR-1 Due Dates
| Taxpayer Type | Period | Due Date |
|---|---|---|
| Turnover > Rs. 5 crore | Monthly | 11th of next month |
| Turnover ≤ Rs. 5 crore (not opted QRMP) | Monthly | 11th of next month |
| Turnover ≤ Rs. 5 crore (opted QRMP) | Quarterly | 13th of month after quarter |
Critical importance: If you do not file GSTR-1, your buyer's ITC is blocked (invoice will not appear in their GSTR-2B). This makes GSTR-1 filing a responsibility not just to the government but to your BUYERS. Late GSTR-1 = late ITC for your customers = unhappy customers.
IFF (Invoice Furnishing Facility) for QRMP
Quarterly filers can optionally upload B2B invoices in months 1 and 2 of the quarter through IFF — so their buyers get ITC monthly (not after quarter-end). IFF is optional but commercially important — B2B buyers demand timely ITC.
GSTR-3B — Summary Return with Tax Payment (Section 39)
The actual tax payment return. Report: total outward supply (taxable + exempt + nil-rated + non-GST), ITC claimed, tax payable, tax paid (cash + ITC utilization). This is where you actually PAY GST.
GSTR-3B Due Dates
| Category | Due Date |
|---|---|
| Turnover > Rs. 5 crore (monthly) | 20th of next month |
| QRMP — Category A states (Chhattisgarh, MP, Gujarat, MH, Karnataka, Goa, Kerala, TN, Telangana, AP, UTs of Daman, DNH, Puducherry, Andaman) | 22nd of month after quarter |
| QRMP — Category B states (all remaining) | 24th of month after quarter |
GSTR-3B Filing Process
Step 1: System auto-populates values from GSTR-1 (outward) and GSTR-2B (inward ITC). You verify and adjust if needed.
Step 2: Enter exempt, nil-rated, and non-GST inward supplies.
Step 3: Enter ITC availed — eligible ITC (from GSTR-2B) and ineligible ITC reversed.
Step 4: Compute tax payable = Output tax - ITC. Utilize ITC in order: IGST first → then CGST for CGST → SGST for SGST. Cross-utilization: IGST can be used for CGST and SGST. CGST cannot be used for SGST (and vice versa).
Step 5: Pay balance in cash through electronic cash ledger (challan via GST portal using net banking/NEFT/RTGS).
Step 6: File return — cannot be revised after filing (corrections in next month's return).
Late Filing Consequences
GSTR-1 late fee: Rs. 50/day (Rs. 25 CGST + Rs. 25 SGST) for regular. Rs. 20/day for nil return. Maximum: Rs. 10,000 per return (Rs. 500 for nil). Plus, your buyer's ITC is blocked until you file.
GSTR-3B late fee: Rs. 50/day (Rs. 20 for nil). Maximum: Rs. 10,000 per return (Rs. 500 for nil). Plus interest at 18% per annum on tax paid late.
Non-filing for 2+ months: system blocks your GSTR-1 filing for subsequent months (cannot report new sales until old returns are filed). Non-filing for 6 months: officer can initiate registration cancellation.