GST IFF due 13th: how QRMP taxpayers pass B2B invoices to buyers between quarters

Monday, 20 July 2026 is a hard date on the indirect-tax calendar, and the taxpayers who feel it most are the small and mid-sized suppliers who file under the Quarterly Return, Monthly Payment (QRMP) scheme. QRMP is open to every registered person whose aggregate turnover is up to Rs 5 crore, and it lets them file GSTR-1 and GSTR-3B once a quarter instead of every month. The trade-off sits in one facility that too many businesses ignore: the optional Invoice Furnishing Facility (IFF), which must be used by the 13th of the following month for the first two months of a quarter. Miss it, and your business customers wait up to two extra months for their input tax credit (ITC). This watchlist explains what falls due on 20 July 2026 and how the 13th-of-the-month IFF rhythm decides whether your buyers can claim credit on time.

Statutory Deadlines

The single most-watched filing on Monday, 20 July 2026 is the monthly GSTR-3B for the June 2026 tax period. Under Section 39 of the Central Goods and Services Tax Act 2017, read with Rule 61 of the CGST Rules, taxpayers who are not enrolled in QRMP file GSTR-3B and discharge their tax by the 20th of the succeeding month. For the June 2026 period that lands on 20 July 2026, and because the 20th is a working Monday there is no weekend extension to lean on.

Two other 20th-of-the-month returns share the date. GSTR-5, the return for a non-resident taxable person, is due for June 2026, and GSTR-5A, the return for providers of online information and database access or retrieval (OIDAR) services to unregistered Indian recipients, is also due for June 2026. All three obligations flow from the same Section 39 framework of the CGST Act 2017.

QRMP taxpayers do not file GSTR-3B on 20 July 2026, and that is precisely the point. Their quarterly GSTR-3B for the April-June 2026 quarter was already due earlier in July, on the 22nd or the 24th depending on the State or Union Territory in which they are registered. What a QRMP business must instead keep in view is the recurring 13th deadline: for the new July-September 2026 quarter, invoices raised in July 2026 can be pushed to buyers through the IFF only up to 13 August 2026.

If you are unsure which bucket you belong to, the test is turnover: QRMP eligibility is capped at aggregate turnover of Rs 5 crore. Cross that line in a financial year and you move to monthly GSTR-3B on the 20th. Understanding the difference between the financial year and the assessment year matters here, because eligibility is measured on the preceding financial year's turnover.

Market Events

There is no RBI Monetary Policy Committee decision, no SEBI board meeting and no scheduled central-bank action confirmed for 20 July 2026 in our editorial briefing, so this watchlist will not manufacture one. The market-moving event on Monday is quieter and entirely mechanical: the GST Network (GSTN) portal absorbs its monthly filing peak as lakhs of non-QRMP taxpayers push GSTR-3B before the 20 July 2026 cut-off, and working capital shifts as tax is paid in cash where the electronic credit ledger falls short.

The IFF is the lever that connects one business's compliance to another's cash flow. As the GSTN QRMP guidance explains, the Invoice Furnishing Facility lets a QRMP supplier upload the B2B invoices raised in the first two months of a quarter by the 13th of the next month, so that the recipient sees those documents in GSTR-2B and can claim ITC in the same month rather than waiting for the quarter-end GSTR-1. For a July 2026 invoice, using the IFF by 13 August 2026 means the buyer claims credit in August; skipping it pushes that credit into October, an ITC delay of up to two months.

That delay is not academic. A recipient who cannot claim credit on time must fund the tax portion out of working capital, and for a business running on thin margins a two-month lag on lakhs of rupees of ITC is a real financing cost. Freed-up or delayed credit is exactly the kind of variable cash a treasury team models before deploying surplus into markets, and tools such as our lumpsum investment calculator help quantify what a one-time deployment of that cash could compound to.

Earnings

No corporate results are confirmed in today's editorial briefing for 20 July 2026, so this watchlist does not list any company earnings; inventing an earnings calendar would breach the zero-hallucination standard this desk holds itself to. For confirmed scheduled results, readers should rely on the exchange filings published directly by BSE and NSE rather than on secondary aggregators.

The "earnings" that a compliance-minded business should watch on 20 July 2026 are its own. Every rupee of ITC claimed on time is a rupee that does not have to be paid in cash, so the discipline of filing GSTR-3B for June 2026 by the 20th, and of using the IFF by the 13th each month, feeds straight into reported operating cash flow. A supplier who furnishes B2B invoices promptly protects the ITC of a chain of buyers whose own margins depend on it.

For the surplus that timely credit frees up, a systematic approach usually beats an ad-hoc one. A recurring monthly commitment through our SIP calculator shows how a fixed sum invested each month compounds over time, and the step-up SIP calculator models raising that contribution as turnover, and therefore free cash, grows year on year.

The QRMP rhythm, in one table

The whole scheme becomes intuitive once the quarter is laid out. For the July-September 2026 quarter, a QRMP taxpayer sees the following pattern; the two IFF windows are optional, but skipping them delays buyers' ITC.

Two forward markers also deserve a place on the calendar even though they do not fall on 20 July 2026. The second instalment of advance tax for FY 2026-27 is due on 15 September 2026, by when a taxpayer should have paid 45 per cent of the estimated liability. And the income-tax return-filing season runs in parallel, so businesses reconciling GST turnover against their books should keep the ITR timeline in view alongside the GST calendar.

FAQ

What is the IFF due date for July 2026 invoices?

The Invoice Furnishing Facility for the first month of the July-September 2026 quarter is available up to 13 August 2026. A QRMP taxpayer who uploads July B2B invoices by that date lets recipients claim ITC in August rather than waiting for the quarterly GSTR-1.

Who is eligible for the QRMP scheme?

Any registered person whose aggregate turnover is up to Rs 5 crore in the preceding financial year can opt for QRMP, filing GSTR-1 and GSTR-3B quarterly while paying tax monthly. The Rs 5 crore ceiling is the single eligibility test.

Is using the IFF compulsory?

No. The IFF is an optional facility for the first two months of a quarter. If a QRMP supplier does not use it, the B2B invoices simply flow through the mandatory quarterly GSTR-1, but the buyer's ITC is then delayed by up to two months.

What falls due on 20 July 2026?

Monthly GSTR-3B for the June 2026 period is due on 20 July 2026 for taxpayers not under QRMP, under Section 39 of the CGST Act 2017. GSTR-5 for non-resident taxable persons and GSTR-5A for OIDAR service providers are also due on the same date.

When is the quarterly GSTR-3B due for QRMP taxpayers?

For the July-September 2026 quarter it falls on 22 or 24 October 2026, staggered by the State or Union Territory of registration. That is why QRMP taxpayers do not file GSTR-3B on 20 July 2026.

How does a delayed IFF affect my buyer?

A July 2026 invoice not uploaded through the IFF by 13 August 2026 will only reach the buyer's GSTR-2B after the quarterly GSTR-1 filing due 13 October 2026, so the buyer's ITC claim can slip by up to two months, forcing them to fund the tax portion from working capital.

What is the next advance-tax deadline after this?

The second instalment of advance tax for FY 2026-27 is due on 15 September 2026, by which point 45 per cent of the estimated annual liability should be paid. It does not coincide with the 20 July 2026 GST filing but belongs on the same forward calendar.