What is due: GSTR-1 monthly filing falls on July 11, what every GST taxpayer must reconcile first

The trading calendar rarely waits for the compliance calendar, but on 11 July 2026 the two collide for every registered business in India. That Saturday is the statutory due date for monthly GSTR-1, the outward-supplies return covering June 2026 sales, and it is the single most consequential filing in the first half of any month because it seeds the input-tax-credit chain for millions of buyers downstream. Miss it, file it carelessly, or push wrong invoice data, and the cost lands not only on your own books but on every customer who relies on your return to claim credit.

This watchlist breaks down exactly what falls due around 11 July 2026, what a monthly filer must reconcile before hitting submit, and how the statutory machinery behind GSTR-1 actually works. The 11th-of-the-succeeding-month rule for monthly filers and the 13th-of-the-month-after-quarter rule for Quarterly Return Monthly Payment (QRMP) filers are set out on the official GST portal tutorial and flow from Section 37 of the Central Goods and Services Tax Act, 2017. Every figure below is tied to that statute or to a verified rate source; where a number cannot be confirmed, it has been left out.

Statutory Deadlines

The headline deadline is unambiguous. For taxpayers who file GSTR-1 monthly, the return for outward supplies made in June 2026 is due on 11 July 2026. This is the 11th day of the month succeeding the tax period, exactly as Section 37 of the CGST Act, 2017 read with the GST portal tutorial prescribes. For QRMP taxpayers, whose aggregate turnover is up to Rs 5 crore in the preceding financial year, the quarterly GSTR-1 for the April-June 2026 quarter falls due on 13 July 2026, the 13th day of the month following quarter-end.

QRMP filers also have an optional Invoice Furnishing Facility (IFF) for the first two months of each quarter, with a cut-off on the 13th of the succeeding month, so any June 2026 invoices not already pushed through the IFF must appear in the quarterly GSTR-1 by 13 July 2026. Monthly GSTR-3B, the summary-cum-payment return, is separately due on 20 July 2026 for monthly filers, which means the 11 July GSTR-1 and the 20 July GSTR-3B sit nine days apart and must agree with each other to the rupee.

The table below maps the GST return calendar that a June 2026 tax period generates. All dates are statutory and remain subject to any government notification extension issued under Section 37 or Section 39 of the CGST Act, 2017.

Late filing is not cost-free. Section 47 of the CGST Act, 2017 levies a per-day late fee for delayed furnishing of GSTR-1, and the rate stood reduced to Rs 50 per day (Rs 25 CGST plus Rs 25 SGST) for returns with tax liability and Rs 20 per day (Rs 10 plus Rs 10) for a nil return, with turnover-linked maximum caps. The interest clock under Section 50 runs separately on any tax actually short-paid through GSTR-3B, so a clean GSTR-1 that feeds an accurate GSTR-3B is the cheapest way to stay compliant.

One income-tax deadline also belongs on a July watchlist for planning purposes: the first advance-tax instalment of FY 2026-27 was due on 15 June 2026, and the second instalment falls on 15 September 2026. Businesses reconciling June GST data are well placed to also true-up their advance-tax estimate, since both rest on the same June quarter revenue. Read the mechanics in the Oquilia glossary entry on advance tax, and check how withholding interacts with it via the note on TDS.

Market Events

GSTR-1 is not usually filed under the heading of market events, yet for working-capital desks it functions as one. Because the return auto-populates a buyer's GSTR-2B, the data filed by 11 July 2026 determines whether thousands of recipient businesses can claim input tax credit in their own 20 July 2026 GSTR-3B. A supplier who files late or wrong effectively freezes a slice of his customers' credit, which is why procurement and treasury teams treat the 11th as a liquidity date, not merely a tax date.

The wider rate backdrop into which this filing lands is a held policy stance. The RBI Monetary Policy Committee left the repo rate unchanged at 5.25% with a neutral stance, the latest in a sequence of pauses after the cumulative 125 basis points of cuts delivered through 2025 took the rate down from 6.50%. A held repo rate of 5.25% keeps externally benchmarked working-capital loan rates broadly stable into July 2026, so any cash-flow squeeze from delayed input credit is not being cushioned by falling borrowing costs.

For investors rather than tax teams, the read-through is indirect but real: companies that mishandle GST compliance carry avoidable working-capital drag, and the discipline of monthly reconciliation is a quiet proxy for operational quality. If you are modelling how that retained cash could compound when redeployed, the Oquilia SIP calculator and step-up SIP calculator let you project monthly contributions, while the lumpsum calculator handles one-off deployments such as a credit refund finally released after reconciliation.

Earnings

No company earnings releases have been confirmed in the editorial briefing for the 11 July 2026 window, so this watchlist will not name results or dates that cannot be verified. What can be stated with certainty is the calendar context: the first quarter of FY 2026-27 closed on 30 June 2026, which means the June GSTR-1 filed on 11 July 2026 captures the final month of Q1 sales, and listed companies will, over the following weeks, begin publishing the Q1 results that rest on the same revenue base.

The practical link for a watchlist reader is that the GST outward-supplies figure a business reports for June 2026 should reconcile with the revenue it eventually recognises for the quarter ended 30 June 2026. A persistent gap between GSTR-1 turnover and reported sales is a classic reconciliation red flag that surfaces in GST audits under Section 35 and Section 44 of the CGST Act, 2017. Treat the 11 July filing as the first hard data point of the Q1 FY27 reporting cycle rather than waiting for formal results.

When results do arrive and a business has surplus to deploy, projecting the growth of that surplus is where the modelling tools earn their keep; the lumpsum calculator and SIP calculator cover the two most common reinvestment patterns. For terminology that recurs across results season, the Oquilia glossary note on cess explains the 4% health-and-education cess that sits on top of corporate tax computations.

Reconciliation checklist before you file

Before submitting GSTR-1 on 11 July 2026, a monthly filer should reconcile five data sets, each of which can silently corrupt the return. First, match every B2B invoice in the books against the e-invoice IRN generated on the Invoice Registration Portal, because invoices above the e-invoicing threshold without a valid IRN are not legally valid for credit. Second, reconcile e-way-bill data against invoice values for goods movements, since material mismatches invite scrutiny under the CGST Act, 2017.

Third, account for every credit note and debit note raised in June 2026, because these adjust the recipient's available credit and omitting them inflates output liability. Fourth, confirm the HSN-wise summary is complete to the mandated digit level for your turnover band. Fifth, cross-check that the GSTR-1 outward-tax total will tie to the liability you intend to declare in the 20 July 2026 GSTR-3B, since the portal now flags GSTR-1 versus GSTR-3B mismatches automatically.

FAQ

What is the GSTR-1 due date for June 2026?

For taxpayers filing monthly, the GSTR-1 for the June 2026 tax period is due on 11 July 2026, being the 11th day of the succeeding month under Section 37 of the CGST Act, 2017 and the official GST portal tutorial. QRMP quarterly filers report the April-June 2026 quarter by 13 July 2026.

Who can file GSTR-1 quarterly instead of monthly?

Taxpayers with an aggregate turnover of up to Rs 5 crore in the preceding financial year may opt into the QRMP scheme and file GSTR-1 quarterly, due on the 13th of the month after the quarter ends. They may still push invoices monthly through the optional Invoice Furnishing Facility by the 13th of the succeeding month.

What is the late fee for filing GSTR-1 after the due date?

Section 47 of the CGST Act, 2017 levies a per-day late fee, which stood reduced to Rs 50 per day (Rs 25 CGST plus Rs 25 SGST) for a return with liability and Rs 20 per day (Rs 10 plus Rs 10) for a nil return, subject to turnover-linked maximum caps. The fee accrues daily until the return is filed.

Why does my GSTR-1 affect my customers?

Because GSTR-1 auto-populates each buyer's GSTR-2B, the invoices you file by 11 July 2026 determine whether your customers can claim input tax credit in their own July GSTR-3B. Late or incorrect filing can block or delay that credit, creating a working-capital cost for your buyers.

How does GSTR-1 relate to GSTR-3B?

GSTR-1 reports invoice-level outward supplies, while GSTR-3B is the monthly summary-cum-payment return due on 20 July 2026 for June. The outward-tax total in GSTR-1 should reconcile with the liability declared in GSTR-3B; the portal automatically flags mismatches between the two.

Can the GSTR-1 due date be extended?

Yes. The 11 July 2026 date is the statutory default under Section 37 of the CGST Act, 2017, but the government can issue a notification extending it for a class of taxpayers or a state, as has happened in earlier periods. Always check for a fresh notification before assuming the standard date applies.

Is any advance-tax deadline relevant in July 2026?

The first advance-tax instalment of FY 2026-27 fell due on 15 June 2026 and the second is due on 15 September 2026, so July itself has no advance-tax cut-off. It is, however, a sensible month to true-up estimates using the same June quarter revenue you reconcile for GST.