The GST regime has more than ten return forms on the books, but most regular taxpayers spend their compliance year inside three or four of them. The challenge is not the number of returns — it is that each return has its own applicability test, its own frequency, its own due date, and its own set of recent amendments that change the calendar in subtle ways. This article maps every return that a regular or composition taxpayer is likely to encounter to who files it, when, and the specific notifications that make those due dates operative for FY 2025-26 and beyond.

All due dates below are CGST positions read with the corresponding CGST Rules; the SGST and UTGST calendars run on the same dates because Section 39 and the underlying Rules apply mutatis mutandis under each State Act. Every figure here has been pulled from the operative section, rule, or notification — not from a calendar app.

1. The Two Compliance Tracks: Regular vs. Composition

Every GSTIN sits on one of two main compliance tracks, with a handful of specialised tracks layered on top:

  • Regular taxpayer (default). Files GSTR-1 (or its quarterly equivalent under QRMP) for outward supplies, GSTR-3B for summary self-assessment, GSTR-9 as the annual return, and GSTR-9C as a reconciliation statement if turnover crosses the threshold.
  • Composition taxpayer (Section 10). Files CMP-08 quarterly to deposit self-assessed tax, and GSTR-4 once a year. No GSTR-1 or GSTR-3B; no input tax credit either.
  • Specialised registrations. Non-resident taxable persons file GSTR-5; OIDAR service providers file GSTR-5A; Input Service Distributors file GSTR-6; TDS deductors under Section 51 file GSTR-7; e-commerce operators collecting TCS under Section 52 file GSTR-8; cancelled registrations close out with GSTR-10.

The first decision a registered person makes is which track applies — and that decision is locked in at registration or by opting into the Composition Scheme via Form CMP-02. The tracks do not blend: a composition taxpayer cannot file GSTR-3B, and a regular taxpayer cannot file CMP-08.

2. GSTR-1 — Outward Supplies Return (Section 37)

GSTR-1 is the return of outward supplies. It captures invoice-level details of every taxable supply made during the tax period — B2B invoices, B2C large invoices above the prescribed threshold, exports, credit and debit notes, and HSN-wise summary. The data flows downstream into the recipient's GSTR-2B and forms the input for the recipient's ITC.

Applicability. Every regular registered person must file GSTR-1, regardless of turnover. There is no minimum threshold to escape it.

Frequency and due date.

  • Monthly filer: 11th of the month following the tax period. A registered person with aggregate turnover above Rs. 5 crore in the preceding financial year must file monthly.
  • Quarterly filer under QRMP: 13th of the month following the quarter. A person with aggregate turnover up to Rs. 5 crore can opt into the QRMP scheme and file GSTR-1 quarterly.
  • Invoice Furnishing Facility (IFF) for QRMP filers: Optional B2B invoice upload for the first two months of a quarter, due 13th of the next month, capped at Rs. 50 lakh per month. The IFF lets recipients claim ITC mid-quarter without waiting for the quarterly GSTR-1.

GSTR-1A — the optional amendment window. Notification 12/2024-Central Tax dated 10 July 2024 introduced Form GSTR-1A as an optional facility to amend or add particulars of a tax period after GSTR-1 is filed but before GSTR-3B is furnished for the same period. GSTR-1A is available from the July 2024 tax period onwards. It does not replace the next period's amendment tables in GSTR-1 — it sits alongside them, giving taxpayers a same-period correction window. There is no separate due date and no late fee on GSTR-1A; it is only available between GSTR-1 filing and GSTR-3B filing.

3. GSTR-3B — Summary Return and Tax Payment (Section 39, Rule 61)

GSTR-3B is the operational return — it is where the tax actually gets paid and where ITC gets claimed. The form summarises outward supplies, ITC availed, and net tax liability, and the cash plus credit ledger debits happen on submission.

Applicability. Every regular registered person files GSTR-3B. Composition taxpayers do not file GSTR-3B; they use CMP-08 instead.

Frequency and due date — monthly filer: 20th of the month following the tax period. The monthly track applies by default to anyone with aggregate turnover above Rs. 5 crore in the preceding financial year.

Frequency and due date — QRMP filer: Quarterly, with two due dates depending on the principal place of business:

  • Category A states (22nd of month following quarter): Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra, Karnataka, Goa, Kerala, Tamil Nadu, Telangana, Andhra Pradesh, Daman and Diu, Dadra and Nagar Haveli, Puducherry, Andaman and Nicobar Islands, and Lakshadweep.
  • Category B states (24th of month following quarter): Himachal Pradesh, Punjab, Uttarakhand, Haryana, Rajasthan, Delhi, Uttar Pradesh, Bihar, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Assam, West Bengal, Jharkhand, Odisha, Jammu and Kashmir, Ladakh, and Chandigarh.

Monthly tax payment for QRMP filers — Form PMT-06. Even though the return is quarterly, tax must still flow into the exchequer monthly. For the first two months of every quarter, QRMP filers deposit self-assessed tax using Form PMT-06 by the 25th of the following month. The third month's tax is paid through GSTR-3B itself when the quarterly return is filed. PMT-06 supports two computation methods: a fixed-sum option (35% of the cash paid through the electronic cash ledger in the preceding quarter's GSTR-3B for those already on QRMP, or 100% of the cash paid in the last month's GSTR-3B for taxpayers who were monthly in the immediately preceding quarter) or a self-assessment option based on the actual outward and inward supplies for the month.

Two recent changes that materially shift compliance.

  • GSTR-3B becomes non-editable from the July 2025 tax period. The values auto-populated from GSTR-1, GSTR-1A, and the Invoice Management System (IMS) flow into GSTR-3B and can no longer be edited downward at the GSTR-3B stage. Corrections must be made before the GSTR-3B is filed — by amending GSTR-1, by filing GSTR-1A, or by accepting/rejecting/keeping-pending invoices in IMS. This pushes a significant amount of compliance work upstream into the GSTR-1 and IMS workflows.
  • Three-year hard limit on filing returns. The Finance Act 2023 amendment, operative from 1 October 2023, bars filing of GSTR-1 (Section 37), GSTR-3B and other Section 39 returns, GSTR-8 (Section 52), and GSTR-9/9C (Section 44) after three years from the original due date. The GST portal enforces this restriction with effect from the October 2025 tax period — returns older than three years cannot be filed at all. The window simply closes.

4. CMP-08 — Composition Scheme Quarterly Statement (Section 39(2), Rule 62)

CMP-08 is not a return in the conventional sense — it is a statement of self-assessed tax for the quarter. The composition taxpayer pays the tax computed at the prescribed composition rate on the quarter's turnover and discharges the liability through this form.

Applicability. Every taxpayer who has opted into the Composition Scheme under Section 10 — both the Section 10(1) scheme for goods and the Section 10(2A) scheme for services. The eligibility ceiling is aggregate turnover up to Rs. 1.5 crore in the preceding financial year for goods (Rs. 75 lakh for special category states) and up to Rs. 50 lakh for service-only composition under Section 10(2A).

Frequency and due date. Quarterly. Due 18th of the month succeeding the quarter. Rule 62 read with the proviso to Section 39(2) prescribes this date.

CMP-08 captures only the tax payable — there is no invoice-level or HSN-level reporting at this stage. The annual reconciliation happens through GSTR-4.

5. GSTR-4 — Composition Annual Return (Section 39(2), Rule 62)

GSTR-4 is the annual return for composition taxpayers, capturing details of inward and outward supplies for the financial year along with tax paid through the four CMP-08 statements.

Applicability. Composition taxpayers under Section 10. The form is annual regardless of how many quarterly CMP-08s were filed during the year.

Due date — the change that catches people out. For FY 2019-20 through FY 2023-24, GSTR-4 was due on 30 April of the following financial year. Notification 12/2024-Central Tax dated 10 July 2024 amended Rule 62 to extend the due date to 30 June of the following financial year, with effect from FY 2024-25 onwards.

The shift to 30 June is the operative date for FY 2024-25 (due 30 June 2025), FY 2025-26 (due 30 June 2026), and subsequent years unless further amended. The 30 April date applies only to back-period filings for FY 2023-24 and earlier — and even there, the practical question is whether the GSTR-10-style three-year limit shuts the window before then.

Late fee for delayed GSTR-4 is Rs. 50 per day (Rs. 25 each under CGST and SGST), capped at Rs. 2,000 per return where there is a tax liability and at Rs. 500 for nil returns.

6. GSTR-9 — Annual Return for Regular Taxpayers (Section 44)

GSTR-9 is the consolidated annual return that aggregates a regular taxpayer's monthly or quarterly returns into a single year-level summary. It reconciles outward supplies, ITC, tax paid, demands, refunds, and any late corrections that flowed through subsequent-period returns.

Applicability. Every regular registered person under Section 44(1) — but with a long-running notification-based exemption for smaller taxpayers.

The Rs. 2 crore exemption is a year-on-year notification, not a permanent feature of the Act. CBIC has historically issued a fresh notification each financial year exempting persons with aggregate annual turnover up to Rs. 2 crore from filing GSTR-9. For FY 2024-25, this exemption is granted by Notification 15/2025-Central Tax. The exemption does not automatically roll over to FY 2025-26 — a corresponding notification has to be issued each year. Treat the threshold as live for FY 2024-25 only and confirm the equivalent notification on the CBIC site for any later year before assuming the exemption applies.

Format updates for FY 2024-25 onwards follow Notification 16/2025-Central Tax, which restructured the form to align with the Invoice Management System and the post-Section 16(4) ITC reconciliation tables.

Due date. 31 December of the financial year immediately following the relevant FY (Section 44(1)). For FY 2024-25 the due date is 31 December 2025; for FY 2025-26, 31 December 2026.

7. GSTR-9C — Reconciliation Statement (Rule 80(3))

GSTR-9C reconciles the figures declared in GSTR-9 with those in the audited financial statements of the registered person. Until FY 2019-20, the form was certified by a Chartered Accountant or Cost Accountant. Since FY 2020-21, it is self-certified by an authorised signatory of the taxpayer — there is no statutory CA audit requirement under GST law any more, though reconciliation discipline still matters because mismatches drive scrutiny.

Applicability. Every registered person whose aggregate turnover during the financial year exceeds Rs. 5 crore. The Rs. 5 crore threshold was set by Notification 30/2021-Central Tax dated 30 July 2021 (replacing the earlier Rs. 2 crore threshold that briefly applied) and continues to apply for FY 2024-25 and beyond.

Due date. 31 December of the financial year following the relevant FY — same date as GSTR-9. The two filings are typically furnished together.

Format updates. Notification 13/2025-Central Tax dated 22 September 2025 revised the GSTR-9C structure for FY 2024-25 onwards to tighten the reconciliation tables and align line-level disclosures with the underlying GSTR-9 changes.

The late-fee point that builds up quietly. Where GSTR-9C is required, Circular 246/03/2025-GST dated 30 January 2025 has clarified that the late fee under Section 47(2) continues to run until the complete annual return — i.e., both GSTR-9 and GSTR-9C — is furnished. Filing GSTR-9 alone without the reconciliation statement does not stop the late-fee clock. For taxpayers above Rs. 5 crore, this is a frequent late-fee surprise that surfaces only at the next audit. See the GST penalties and late fees reference for the turnover-banded amounts.

8. Specialised Returns at a Glance

Most regular and composition taxpayers will never touch the returns below — but if you carry one of these specialised registrations or work with a client who does, the calendar matters.

  • GSTR-5 (Non-Resident Taxable Person): Monthly. Due the earlier of (i) 13th of the month following the tax period or (ii) 7 days after the last day of the registration period. The 13th came in via the Finance Act 2022 amendment to Section 39(5) with effect from 1 October 2022 — earlier the date was the 20th.
  • GSTR-5A (OIDAR service providers): Monthly. Due 20th of the next month.
  • GSTR-6 (Input Service Distributor): Monthly. Due 13th of the next month. Captures invoice-wise ITC received and the manner of distribution to recipient GSTINs.
  • GSTR-7 (TDS deductor under Section 51): Monthly. Due 10th of the next month. Filed by government departments, local authorities, and notified persons that deduct TDS at 2% (1% CGST plus 1% SGST, or 2% IGST) on the value of supply where it exceeds Rs. 2.5 lakh under a contract.
  • GSTR-8 (TCS by e-commerce operator under Section 52): Monthly. Due 10th of the next month. Filed by e-commerce operators collecting TCS at 0.5% combined (0.25% CGST plus 0.25% SGST, or 0.5% IGST) on net taxable supplies through their platform — reduced from the earlier 1% combined rate via Notification 15/2024-Central Tax dated 10 July 2024.
  • GSTR-10 (Final return on cancellation, Section 45): Filed within 3 months from the date of cancellation or the date of the cancellation order, whichever is later. This is a one-time return; it captures stock and any residual liability at the point of exit. Late fee under Notification 08/2023-CT is Rs. 200 per day combined, capped at Rs. 1,000 per return for regular GSTR-10 amnesty windows; the operative cap is to be checked against the latest position at the time of filing.

9. The Compliance Calendar at a Glance

The table below consolidates every return covered above into a single calendar reference. Cross-check the active CGST notifications before treating any threshold or due date as fixed for a future financial year — the historical pattern is that exemptions and turnover bands are revised by annual notification rather than statute.

Return Who Files Frequency Due Date GSTR-1 Regular taxpayer (monthly above Rs. 5 Cr) Monthly 11th of next month GSTR-1 (QRMP) Regular taxpayer up to Rs. 5 Cr opting in Quarterly 13th of month after quarter IFF (QRMP) QRMP filer (optional) Monthly (M1, M2) 13th of next month GSTR-1A Regular taxpayer (optional amendment) As needed Between GSTR-1 and GSTR-3B GSTR-3B Regular taxpayer (monthly) Monthly 20th of next month GSTR-3B (QRMP Cat A) QRMP filer in Category A states Quarterly 22nd of month after quarter GSTR-3B (QRMP Cat B) QRMP filer in Category B states Quarterly 24th of month after quarter PMT-06 QRMP filer (M1, M2 of quarter) Monthly 25th of next month CMP-08 Composition taxpayer Quarterly 18th of month after quarter GSTR-4 Composition taxpayer Annual 30 June of next FY (FY 2024-25 onwards) GSTR-5 Non-resident taxable person Monthly 13th of next month or 7 days after registration ends GSTR-5A OIDAR service provider Monthly 20th of next month GSTR-6 Input Service Distributor Monthly 13th of next month GSTR-7 TDS deductor (Section 51) Monthly 10th of next month GSTR-8 E-commerce operator (TCS, Section 52) Monthly 10th of next month GSTR-9 Regular taxpayer (above Rs. 2 Cr for FY 2024-25) Annual 31 December of next FY GSTR-9C Regular taxpayer above Rs. 5 Cr Annual 31 December of next FY GSTR-10 Cancelled registration One-time 3 months from cancellation or order date

10. The Two Decisions That Drive Most of Your Calendar

Once the basic track is locked in (regular vs. composition), two further decisions shape the rest of the year:

Decision 1 — QRMP or monthly? If aggregate turnover in the preceding FY is Rs. 5 crore or below, QRMP is available. The trade-off:

  • QRMP in: One GSTR-1 and one GSTR-3B per quarter (instead of three each), but two PMT-06 deposits per quarter and two optional IFF uploads. Net result is fewer return-filings but the same number of cash-flow events. Helpful when the bookkeeping load is heavier than the cash-management load.
  • QRMP out: Twelve GSTR-1s and twelve GSTR-3Bs a year, but recipient ITC is current monthly without depending on IFF uploads. Helpful when most of your buyers are larger and care about month-by-month ITC matching.

The opt-in or opt-out is exercised on the GST portal, with cut-off windows in the first month of each quarter. The default for new registrants depends on turnover declared at registration.

Decision 2 — Annual return obligation. For FY 2024-25, taxpayers with aggregate turnover up to Rs. 2 crore are exempt from GSTR-9 (Notification 15/2025-CT), and taxpayers up to Rs. 5 crore are exempt from GSTR-9C (Notification 30/2021-CT continues to apply). That bands taxpayers into three annual-compliance buckets:

  • Up to Rs. 2 crore: No annual return filing for FY 2024-25 (subject to the exemption notification continuing to apply).
  • Rs. 2 crore to Rs. 5 crore: GSTR-9 only.
  • Above Rs. 5 crore: Both GSTR-9 and GSTR-9C, with the late-fee clock running on the bundle as a whole.

11. Common Compliance Traps in 2026

Three traps account for most of the avoidable late fees and notices in the current cycle:

  • Trap 1 — Treating GSTR-3B as the place to fix GSTR-1 errors. With non-editable GSTR-3B from July 2025 onwards, GSTR-1A and IMS actions need to happen before GSTR-3B is filed, not after. The mental model that "I will adjust in 3B" no longer works.
  • Trap 2 — Assuming the GSTR-9 exemption rolls over. Each year's exemption is a separate notification. Diary the next year's exemption check before the FY-end so the filing decision is made on the basis of the live notification, not last year's.
  • Trap 3 — Filing GSTR-9 without GSTR-9C. For taxpayers above Rs. 5 crore, the late fee continues to accrue until both forms are on the portal. Plan the GSTR-9 and GSTR-9C as a single workstream, not as two separate filings.

Beyond the traps, the broader compliance picture for 2026 includes the Invoice Management System pulling forward the work that used to happen in GSTR-3B reconciliation, the 30-day IRN reporting rule biting at lower turnover bands, and the GST Appellate Tribunal coming online for the first wave of disputed adjudications. For the wider context on these, see the April 2026 compliance playbook and the GSTAT first-filer roadmap.

Bottom Line

The GST return calendar looks intimidating because there are eighteen-plus form names floating around, but the operative count for any single taxpayer is much smaller. A regular monthly filer touches GSTR-1 and GSTR-3B every month and GSTR-9 (with possibly GSTR-9C) once a year. A QRMP filer touches GSTR-1 and GSTR-3B once a quarter, with PMT-06 and optional IFF in between. A composition taxpayer touches CMP-08 once a quarter and GSTR-4 once a year. Specialised returns apply only where a specialised registration exists.

The dates themselves are stable — most have been unchanged for years. What changes annually is the threshold and exemption layer: the GSTR-9 below-Rs. 2-crore exemption, the GSTR-9C Rs. 5-crore mandate, the QRMP Rs. 5-crore eligibility, and the periodic format updates. Pull the live notification before any year-end filing decision rather than relying on memory of last year's position. The form numbers are constant; the notifications around them are not.