Tax & Compliance·6 min read
GST Filing Calendar 2025: Never Miss a Due Date
Build a repeatable monthly rhythm for GSTR-1 and GSTR-3B so you never block customer ITC or pay ₹50/day late fees that compound quietly.
January 25, 2024
What you'll take away
- GSTR-1 by the 11th (monthly) feeds your buyers' GSTR-2B—late filing hurts their ITC and your relationships.
- GSTR-3B is your cash tax payment; mismatch with 2B is the #1 audit trigger.
- QRMP filers follow quarterly GSTR-1 with monthly tax via PMT-06—know your scheme before onboarding.
- Pelago's compliance calendar syncs GST, TDS, and ROC dates for founder-led teams.
Why timing is a revenue issue, not just compliance
- Late fee: ₹50 per day per act (CGST + SGST), capped but painful on thin margins.
- Interest: 18% per annum on tax paid late.
- Reputation: Large clients run vendor compliance checks before renewals.
Missing GSTR-1 does not only attract late fees—it blocks your customers from claiming Input Tax Credit on your invoices. B2B buyers will chase you, delay payments, or switch vendors.
GSTR-3B is where you declare tax liability and pay cash to the government. Filing without reconciling against GSTR-2B (purchase ITC) is how startups discover ₹1–2 lakh discrepancies during scrutiny.
Monthly due dates (regular taxpayers)
Mark the 8th and 18th on your calendar for data prep—not the due date itself.
| Form | Purpose | Typical due date |
|---|---|---|
| GSTR-1 | Outward supplies (sales) | 11th of next month |
| GSTR-3B | Summary return + tax payment | 20th of next month |
| GSTR-2B | Auto-drafted purchase ITC (read-only) | Generated after supplier files |
| IFF (optional) | QRMP intra-quarter sales | 13th of next month (if opted) |
Founder tip: Reconcile purchases in accounting software every Friday; do not wait for the 19th panic.
GST keeping you up at night?
Monthly filing support with reconciliation before every GSTR-3B.
Book compliance callQRMP scheme: who it helps and who it hurts
- Turnover up to ₹5 crore may opt for QRMP (check latest notifications).
- GSTR-3B quarterly for QRMP: 22nd or 24th after quarter end (state-dependent).
- Annual return GSTR-9 still required if applicable to your turnover tier.
Quarterly Return Monthly Payment (QRMP) suits businesses with steady tax outflow but low B2B invoice volume. You file GSTR-1 quarterly but pay tax monthly via Form PMT-06.
If most of your revenue is B2B, staying on monthly GSTR-1 keeps your buyers' ITC flowing every month—another reason to understand your customer mix before opting in.
Annual returns and audit trail
GSTR-9 (annual return) consolidates monthly data for the financial year. GSTR-9C is a reconciliation statement when turnover exceeds audit thresholds—treat March–May as close-the-books season, not optional admin.
For FY 2024–25, plan ITC reversals, credit notes, and e-invoice gaps before December filing windows—extensions happen but should not be your plan A.
Pelago pairs GST filings with books review so your numbers match what the CA signs on the audit report.
Founder checklist before every 3B
- Match sales register to GSTR-1 already filed or about to file.
- Download GSTR-2B; flag missing supplier filings.
- Reverse ineligible ITC (blocked credits, motor vehicles, etc.).
- Pay via challan before filing; keep ARN screenshot in your data room.
One disciplined rhythm beats twelve emergency filings—and keeps your next fundraise diligence clean.