GSTR-3B Deadline Watch: The 20th, 22nd and 24th Dates Every GST Filer Must Track

For every GST-registered business in India, three dates on the calendar decide whether the month closes clean or with a late-fee meter running: the 20th, the 22nd and the 24th. These are the statutory cut-offs for Form GSTR-3B, the summary return through which more than 1.4 crore active registrations declare their tax and pay it. Miss one and interest accrues at 18% per annum under Section 50 of the CGST Act, 2017, from the day after the due date until the cash actually hits the electronic cash ledger.

This watchlist maps the GST return cycle you need to track into the next filing window, sets it alongside the income-tax advance-tax instalment due in September 2026, and flags the market events worth a diary entry. Every date below is a statutory deadline; none can be assumed away, because Form GSTR-3B must be filed even in a month with zero business, and the due date can be extended only by a Government notification.

Statutory Deadlines

The GSTR-3B due date turns on how you are registered to file. Monthly filers face the 20th of the month following the tax period. Filers who opted into the Quarterly Return Monthly Payment (QRMP) scheme file quarterly, and their due date, as notified for different States and Union Territories, falls on either the 22nd or the 24th of the month following the quarter.

For the tax period of August 2026, monthly GSTR-3B is due on 20 September 2026. QRMP filers do not file a return for August, but they must deposit tax for that second month of the July-September 2026 quarter through Form PMT-06 by 25 September 2026, either on a self-assessment basis or using the 35% fixed-sum method drawn from the previous quarter's cash payment. The quarterly GSTR-3B for the July-September 2026 quarter then follows on 22 or 24 October 2026, depending on the principal place of business.

The 22nd-versus-24th split is not a choice; it is fixed by the State or Union Territory of the principal place of business under Central Board of Indirect Taxes and Customs (CBIC) Notification 76/2020-Central Tax. The two categories run as follows.

Alongside GST, the income-tax calendar carries a hard September deadline that every business and professional with a tax liability above Rs 10,000 for the year must watch. The second instalment of advance tax for financial year 2026-27 is due on 15 September 2026, by which date a cumulative 45% of the estimated annual liability must stand paid under Section 211 of the Income-tax Act, 1961. The schedule for the full year runs as below, and it applies to the financial year 2026-27, that is assessment year 2027-28.

A short note on Form 15G and Form 15H, which readers often expect to see with a "tomorrow" deadline: these are self-declarations to stop tax deduction at source on interest income, and they are filed at the start of the financial year or when the income begins, not on a fixed statutory calendar date. There is no separate next-day filing cut-off for them; the discipline is to lodge them in April so no TDS is withheld across the year. The Income-tax Department publishes the current forms and thresholds at incometax.gov.in.

Market Events

The single dated event that anchors the rate outlook is the next meeting of the Reserve Bank of India's Monetary Policy Committee, scheduled for 5-7 October 2026. At its last meeting on 3-5 August 2026 the MPC held the repo rate unchanged at 5.25% in a unanimous vote, its fourth consecutive pause across February, April, June and August 2026, keeping the policy stance neutral. Governor Sanjay Malhotra said the committee wanted greater clarity on the inflation outlook before acting.

The other standing rates from that August decision are the Standing Deposit Facility at 5.00%, the Marginal Standing Facility at 5.50% and the Bank Rate at 5.50%. For the year, the RBI revised its projections at that meeting, raising FY 2026-27 GDP growth by 10 basis points to 6.7% and lowering CPI inflation by 10 basis points to 5.0%. Because External Benchmark Lending Rate (EBLR) loans reset within about three months of any repo move, a held rate means home-loan and MSME-loan EMIs stay where they are into the festive quarter. The official policy statements and the MPC calendar are published at rbi.org.in.

Beyond the RBI meeting, no SEBI board meeting, OPEC decision or comparable market event is confirmed on the editorial calendar for the immediate watch window. This desk flags such events only when they are on the official record, so none are asserted here. Traders tracking derivatives should note the routine monthly settlement rhythm of the exchanges, but any specific expiry date should be confirmed against the National Stock Exchange circular rather than assumed from this piece.

Earnings

The Oquilia Newsroom flags company results only when the board-meeting intimation is confirmed on the exchange filing record. For the immediate watch window covered here, no quarterly earnings are confirmed on our editorial calendar, so this desk names none rather than publish an unverified schedule. Investors who want the definitive list should check the "Board Meetings" and "Corporate Announcements" sections of the BSE and NSE websites, where every listed company files its result date under Regulation 29 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015, at least two working days in advance.

If you are positioning a portfolio around a results season rather than a single print, the disciplined route is a staggered entry rather than a lump-sum bet on one day's number. Our SIP calculator models a monthly systematic investment, the step-up SIP calculator shows the effect of raising that contribution each year, and the lumpsum calculator lets you compare a one-time deployment against the same amount spread over time. Each keeps the decision anchored to a plan instead of a headline.

The cost of missing the date

The penalty structure is where a missed GSTR-3B stops being a paperwork slip and starts costing cash. Under Section 47 of the CGST Act, the late fee for a return with tax payable is Rs 50 per day (Rs 25 under CGST plus Rs 25 under SGST), and for a nil return it is Rs 20 per day (Rs 10 plus Rs 10), running until the return is filed and subject to the notified caps. Separately, Section 50 charges interest at 18% per annum on the net tax paid late, calculated from the day after the due date. A registration that files late also blocks its own recipients, because input tax credit flows through the system-generated GSTR-2B, which draws from the supplier's GSTR-1.

That linkage matters for working capital. GSTR-3B is auto-populated from the supplier's GSTR-1 or GSTR-1A and from the system-generated GSTR-2B statement. The auto-populated values are editable, but any figure a filer edits is highlighted in red on the portal, a deliberate signal that the declared number departs from the system's own reconciliation. Treat a red field as a flag to keep documentation ready, because it is the first thing a reconciliation notice will question. The full field-by-field guidance is set out in the GST portal user manual at tutorial.gst.gov.in.

The governing law itself, the Central Goods and Services Tax Act, 2017, along with its sections on returns (39), late fee (47) and interest (50), is available in full on the Government of India's official statute repository at indiacode.nic.in. Reading the section text alongside the portal manual is the surest way to resolve any doubt about which date binds a given registration.

FAQ

What is the GSTR-3B due date for monthly filers?

Form GSTR-3B is due on the 20th day of the month following the tax period for monthly filers, under Section 39 of the CGST Act, 2017. For the August 2026 tax period, that means 20 September 2026. The return must be filed even if there was no business in the month, and the due date can be changed only by a Government notification.

Why do QRMP filers have two dates, the 22nd and the 24th?

Quarterly Return Monthly Payment scheme filers file GSTR-3B once a quarter, and CBIC Notification 76/2020-Central Tax splits registrations into two groups by the State or Union Territory of the principal place of business. Category X States and UTs file by the 22nd of the month following the quarter; Category Y file by the 24th. It is fixed by location, not chosen by the taxpayer.

Do QRMP filers pay anything in the months they do not file a return?

Yes. For the first two months of each quarter, QRMP filers deposit tax through Form PMT-06 by the 25th of the following month, either on self-assessment or using the 35% fixed-sum method based on the previous quarter. For the July-September 2026 quarter, the August payment is due by 25 September 2026.

What does it cost to file GSTR-3B late?

Under Section 47 of the CGST Act, the late fee is Rs 50 per day for a return with tax (Rs 25 CGST plus Rs 25 SGST) and Rs 20 per day for a nil return, subject to notified caps. On top of that, Section 50 levies interest at 18% per annum on the tax paid late, running from the day after the due date until payment.

Why is one of my GSTR-3B figures highlighted in red?

The return is auto-populated from your supplier's GSTR-1 or GSTR-1A and from the system-generated GSTR-2B. Those values are editable, but the moment you change one, the portal highlights the edited field in red. It is a signal that your declared figure differs from the system's reconciliation, so keep the supporting documentation ready.

When is the next advance-tax instalment due?

The second advance-tax instalment for financial year 2026-27 is due on 15 September 2026, by which date 45% of the estimated annual liability must be paid under Section 211 of the Income-tax Act, 1961. It applies to anyone whose tax liability for the year is expected to exceed Rs 10,000.

When does the RBI next review the repo rate?

The Monetary Policy Committee's next scheduled meeting is 5-7 October 2026. At its 3-5 August 2026 meeting it held the repo rate at 5.25% for a fourth consecutive time, with the Standing Deposit Facility at 5.00% and the Marginal Standing Facility and Bank Rate at 5.50%.