GSTR 9 Due Date for FY 2025-26: A Reconciliation Checklist for CA Firms

Every December, CA firms across India run into the same wall: dozens of clients, one annual return each, and a portal that does not forgive a careless table. For FY 2025-26 the GSTR 9 due date is 31 December 2026, and teams using AskSolique to track it alongside client-wise GST positions tend to start their reconciliation in October, not in the last week of December. This guide is a working checklist for that reconciliation: who has to file, what to tie out before filing, and where most annual-return problems actually come from.

Who Has to File GSTR-9 for FY 2025-26

GSTR-9 is the annual return for regular taxpayers registered under GST. It is not filed by composition dealers (who file GSTR-4), input service distributors, casual taxable persons, non-resident taxable persons or TDS/TCS deductors.

For smaller businesses, the government has again kept the relief for aggregate turnover up to Rs 2 crore. Notification No. 15/2025-Central Tax, dated 17 September 2025, makes the annual return optional for taxpayers in this band. Many firms still file for such clients voluntarily, because a clean annual return is easier to defend later than an empty file.

The practical bands look like this:

• Turnover up to Rs 2 crore: GSTR-9 optional.
• Turnover above Rs 2 crore and up to Rs 5 crore: GSTR-9 mandatory, GSTR-9C not required.
• Turnover above Rs 5 crore: GSTR-9 plus a self-certified reconciliation statement in GSTR-9C.

If you want a plain-language primer on applicability and turnover limits for clients, this earlier note on GSTR 9 applicability and turnover limits covers the basics in more detail.

Why FY 2025-26 Needs More Care Than Usual

Two things make this year different. First, the rate rationalisation that took effect from 22 September 2025 means many clients ran two rate structures in the same financial year. HSN-wise summaries, rate-wise outward supplies and credit notes issued after the change all need a second look, because a supply invoiced before 22 September and amended after it can easily land in the wrong rate bucket.

Second, the window for correcting the year is narrower than many clients assume. Pending input tax credit for FY 2025-26 can be claimed only up to 30 November 2026 or the date of filing the annual return, whichever is earlier. Filing GSTR-9 early does not just close the return; it also closes the door on any ITC you had not yet picked up in GSTR-3B. And once GSTR-9 is filed, it cannot be revised.

That combination is why experienced partners prefer to finish reconciliation by the end of November, then file in December with the numbers already settled.

The Reconciliation Checklist Before You File

Most GSTR-9 errors are not filing errors. They are reconciliation gaps that were never closed during the year. A sound working paper ties out the following before anyone opens the return:

1. Books vs GSTR-1: outward supplies, debit notes and credit notes, rate-wise. Check amendments made in later months that relate to FY 2025-26.
2. GSTR-1 vs GSTR-3B: tax liability declared vs tax actually paid. Short payment found here should be paid through DRC-03 with interest before filing.
3. GSTR-3B ITC vs GSTR-2B: credit claimed vs credit available. Excess claims should be reversed; unclaimed eligible credit should be taken before the November cut-off.
4. Ineligible and blocked credit: Section 17(5) items, Rule 42/43 reversals and ITC on supplies from vendors who never filed.
5. HSN summary: codes and quantities for both rate periods, matched to sales registers.
6. Late fee exposure: per-day late fee is Rs 50 for turnover up to Rs 5 crore, Rs 100 between Rs 5 crore and Rs 20 crore, and Rs 200 above Rs 20 crore, so a delayed large client gets expensive quickly.

Document each difference with a reason, not just a number. When the department asks a question two years later, a reason written today is worth far more than a figure nobody can explain.

Where Annual Return Mismatches Turn Into Notices

The annual return is the department's cleanest data source on a taxpayer's full year. Differences between GSTR-9, GSTR-3B and GSTR-2B are exactly what automated scrutiny looks for, and they are a common trigger for a GST notice under Sections 61, 73 or 74. Typical triggers include:

• ITC in GSTR-3B higher than what appears in GSTR-2B for the year.
• Turnover in GSTR-9 lower than the e-way bill or e-invoice data for the same GSTIN.
• Tax paid in cash lower than liability shown in GSTR-1.
• Credit notes reported in GSTR-1 without matching reversal by the recipient.

When a client's position depends on an interpretation, for example whether a particular credit is blocked, the working paper should cite the ruling relied on. A focused GST case law search workflow makes it much easier to find the governing decision quickly and attach it to the file before filing, rather than after a notice arrives.

How CA Firms Are Speeding Up the Annual Return Season

The firms that handle GSTR-9 season without late nights usually do three things differently. They run reconciliations quarterly, so December is a review rather than a rebuild. They keep a standard working-paper template for every client, so juniors are not reinventing the format. And they use research tools to answer interpretation questions in minutes instead of hours.

That last point is where AI has started to matter. A partner who has to decide whether a credit is admissible, or how a recent amendment applies to a client's facts, needs the relevant section, rule, circular and judgment in one place. Many firms evaluating the best AI tool for tax research in India for this kind of work look for three things: answers that cite the actual provision and case, coverage of both GST and income tax, and drafting support for replies when a query does come in. If your firm also handles direct-tax work in the same season, the same discipline applies there; this guide on how CA firms can prepare a defensible response to an income tax scrutiny notice follows a similar evidence-first approach.

A Simple Timeline for December 2026

• By 31 October: identify which clients must file GSTR-9 and which also need GSTR-9C; collect books for the full year.
• By 30 November: finish ITC reconciliation and claim any remaining eligible credit; pay short liabilities through DRC-03.
• 1 to 20 December: prepare and review returns, starting with clients above Rs 5 crore.
• Before 31 December: file, download the filed return and save it with the working papers.

Common Questions From Clients

Can we correct a mistake after filing GSTR-9? No. The annual return cannot be revised once filed. Errors found later have to be handled through payment with DRC-03 or explained during scrutiny, which is why the reconciliation must be complete before filing.

Our turnover is under Rs 2 crore. Should we still file? Filing is optional in this band. Voluntary filing can still help where the client has large ITC claims or expects lender or investor diligence, since it gives a single, consolidated view of the year.

Is GSTR-9C still a CA-certified audit? No. Since FY 2020-21 it is a self-certified reconciliation statement, but it still needs to be prepared carefully, because every unexplained difference between books and returns is visible in it.

GSTR-9 rewards preparation more than any other return in the GST calendar. Start early, write down the reasons behind every difference, and keep your research attached to the file. If your firm wants to see how AI-assisted tax research and drafting fits into this workflow, contact us at AskSolique.