GSTR-9 & GSTR-9C Annual Return: Complete Filing Guide for FY 2025-26

Every December, thousands of CAs race against the same deadline — the annual GST return. GSTR-9 sits quietly on every registered taxpayer's compliance calendar until the fourth quarter arrives, and then it demands full attention: twelve months of GSTR-1s, GSTR-3Bs, and purchase registers all have to align in a single consolidated statement. Get it right and you close the year clean. Get it wrong and you face notices, ITC reversals, and penalties that compound with every passing day.

This guide covers everything you need to file GSTR-9 and GSTR-9C for FY 2025-26 — who must file, what goes where, how to reconcile without errors, and exactly what the law says about the consequences of non-compliance.

Who Must File GSTR-9 (and Who Is Exempt)

Every regular GST-registered taxpayer whose aggregate annual turnover in FY 2025-26 exceeds ₹2 crore must file GSTR-9. If your client's turnover falls below ₹2 crore, filing is optional — but the CBIC has repeatedly recommended filing even for small taxpayers to keep records clean.

Who is NOT required to file GSTR-9:

• Composition scheme taxpayers (they file GSTR-9A instead)
• Input Service Distributors (ISD)
• Casual Taxable Persons
• Non-resident taxable persons
• TDS deductors under Section 51
• TCS collectors under Section 52

For clients in the ₹2–5 crore turnover band, GSTR-9 filing is mandatory, but GSTR-9C (the reconciliation statement) is optional — they can file it voluntarily, but it is only compulsory for turnover exceeding ₹5 crore.

GSTR-9C Threshold: ₹5 Crore

From FY 2022-23 onwards, GSTR-9C is mandatory only when aggregate annual turnover exceeds ₹5 crore. Before FY 2021-22, the threshold was ₹2 crore and CA certification was required. Now, GSTR-9C is self-certified by the taxpayer — no separate auditor certification is needed under GST law, though your CA firm will typically prepare and verify the reconciliation.

If your client's turnover in FY 2025-26 is ₹7.2 crore, both GSTR-9 and GSTR-9C are mandatory. If it is ₹3.8 crore, only GSTR-9 is required.

The Structure of GSTR-9: Six Parts You Cannot Ignore

GSTR-9 is a 19-table annual return. Understanding what each part captures prevents the most common filing errors.

Part I — Basic Details: GSTIN, legal name, trade name, and the financial year. Mostly auto-populated.

Part II — Details of Outward and Inward Supplies:

This is where your GSTR-1 data must match your GSTR-3B. Table 4 captures taxable outward supplies (net of amendments and credit/debit notes), Table 5 captures zero-rated supplies, and Table 6 captures inward supplies on which you paid tax under Reverse Charge Mechanism (RCM). Any mismatch between monthly returns and the annual total here triggers system-generated notices.

Part III — ITC Details:

Table 6 captures total ITC availed as per your GSTR-3B filings. Table 7 captures ITC reversed (as per Rules 37, 38, 42, 43, and Section 17(5)). Table 8 is the most scrutinised — it reconciles ITC declared in your GSTR-3B against what was available in GSTR-2B for the year. A positive difference in Table 8D means you claimed ITC that your suppliers did not declare, which is a liability waiting to crystallise.

Part IV — Details of Tax Paid:

This reconciles total tax paid through cash (PMT-06 or GSTR-3B challan) and through ITC utilisation for CGST, SGST, IGST, and cess separately.

Part V — Previous FY Transactions Declared in Current FY:

This section is frequently missed. Transactions for FY 2024-25 declared in GSTR-1 during April–November 2025 (the amendment window under Section 37) must be captured here. Omitting them creates reconciliation gaps that surface in GSTR-9C and invite scrutiny.

Part VI — Other Information:

Late fees paid, demands and refunds, HSN-wise summary of outward supplies (Table 17), and HSN-wise summary of inward supplies (Table 18). HSN summary is mandatory for taxpayers with turnover above ₹5 crore and optional for others, though including it for all clients makes annual audits significantly easier.

GSTR-9C: The Reconciliation Statement Demystified

GSTR-9C is a reconciliation between your audited financial statements and the figures declared in GSTR-9. Think of it as a bridge between your Profit & Loss account or Balance Sheet and your GST returns — two worlds that speak different languages and must be made to agree.

Part A: Reconciliation of Turnover

If your client's books show total revenue of ₹8.5 crore but GSTR-1 shows declared taxable supplies of ₹8.1 crore, you need to explain the ₹40 lakh difference. Common reasons include:

• Revenue from exempted supplies (not reported in GSTR-1)
• Advance receipts that reversed in the same period
• Credit notes issued but not yet reflected in GSTR-3B
• Unbilled revenue and accruals that do not create GST liability

Each adjustment needs a narration in GSTR-9C. A reconciliation gap without explanation is an open invitation for a Section 73 demand notice.

Part B: Reconciliation of ITC

Your books may show total GST paid on purchases of ₹95 lakh — but only ₹88 lakh appears in GSTR-2B and ₹87.5 lakh was actually claimed in GSTR-3B. The ₹7 lakh gap (purchases from unregistered or non-compliant suppliers) and the ₹50,000 voluntary reversal both need to be disclosed and individually explained in Part B. Leaving these unexplained is one of the most common triggers for departmental audit selection.

Self-Certification: What It Actually Means

Since GSTR-9C is now self-certified, the authorised signatory of the business signs off on the reconciliation. In practice, your CA firm prepares the reconciliation, the client reviews it, and the authorised signatory certifies it on the GST portal. Make sure your clients understand they are personally certifying these numbers — errors in GSTR-9C carry the same legal weight as errors in any other GST return, and the defence of 'my CA prepared it' does not exist in tax law.

Step-by-Step Action Plan for Filing GSTR-9 for FY 2025-26

Step 1: Consolidate All GSTR-1 and GSTR-3B Data

Pull consolidated data from the GST portal — the Summary view of all 12 GSTR-1s and GSTR-3Bs for April 2025 to March 2026. Download the GSTR-9 auto-populated PDF from the portal, which becomes available from October or November 2026 onwards. Cross-check the auto-populated figures against your own records before accepting them — the system is accurate but depends on what was filed monthly.

Step 2: Reconcile with Your Books

Match portal data against your client's purchase register, sales register, and ITC ledger in your accounting software. Flag every mismatch, even small ones. A ₹500 difference in tax can indicate a larger booking error — perhaps an invoice posted to the wrong period or a credit note entered with the wrong date.

Step 3: Check GSTR-2B vs ITC Claimed

For every month of FY 2025-26, compare ITC available in GSTR-2B with ITC claimed in GSTR-3B. If excess ITC was claimed in any month, reverse it with interest at 18% per annum from the date of availment under Rule 37A. This reconciliation should ideally happen monthly, not annually.

Step 4: Account for Amendments and Credit/Debit Notes

All B2B amendments, credit notes, and debit notes issued between April and November 2025 for FY 2024-25 transactions must go into Part V of GSTR-9. Those issued between April and November 2026 for FY 2025-26 transactions will be captured in the Part V of the GSTR-9 for the following year. Missing this cross-year matching is the single most common source of reconciliation gaps in GSTR-9C.

Step 5: Prepare GSTR-9C (if applicable)

Map every line of your client's P&L to the taxability schedule under GST. Identify exempt income, non-GST income, and supply-related income separately. Build the turnover reconciliation and ITC reconciliation schedules with narrations for each adjustment item. Templates help here — building one good template and reusing it across clients saves significant time each year.

Step 6: File on the GST Portal

Log in at gst.gov.in, navigate to Annual Returns, select FY 2025-26, and verify the auto-populated data. Correct any errors, attach GSTR-9C if required, and submit using DSC or EVC. The system will not allow GSTR-9C filing if GSTR-9 has not been submitted first.

Due date for FY 2025-26: December 31, 2026.

Common Mistakes That Trigger Notices

Mistake 1: Omitting E-commerce TCS

If your client sells through Amazon or Flipkart, the tax collected at source (TCS) under Section 52 must appear in Table 8H of GSTR-9. Missing it creates a mismatch with TCS certificates issued by the operator and draws automatic reconciliation alerts.

Mistake 2: Skipping Rule 42/43 ITC Reversal in Part III

Businesses with both taxable and exempt supplies must partially reverse ITC on common inputs under Rules 42 and 43. Many filers declare full ITC in GSTR-3B but forget to reflect the reversal in Part III of GSTR-9, creating an inflated ITC claim on record that the department will eventually question.

Mistake 3: Inconsistent HSN Summary

Table 17 (outward supply HSN summary) should match your GSTR-1 HSN summary reports exactly. Inconsistencies draw notices asking for classification clarification, and misclassification disputes carry rate-differential liability.

Mistake 4: Leaving Table 8D Unexplained

Table 8D shows ITC claimed in GSTR-3B that does not appear in GSTR-2B. If the figure is positive, you need either a corresponding reversal or a documented explanation — for example, the supplier filed after the September cutoff but the ITC was genuinely eligible under transitional provisions. Department scrutiny of Table 8D has increased sharply since FY 2023-24.

Mistake 5: Missing the Opening ITC Carry-forward

The opening ITC balance carried forward from the FY 2024-25 annual return must reconcile with your electronic credit ledger balance as on April 1, 2025. A mismatch here points to an uncorrected error from the previous year and cascades into every subsequent reconciliation.

Late Fees, Penalties, and Section 73 Exposure

Late filing of GSTR-9 attracts ₹200 per day (₹100 CGST + ₹100 SGST), subject to a maximum of 0.25% of the taxpayer's turnover in the respective state.

For a client with ₹10 crore annual turnover in Maharashtra who files 60 days late:

• Daily fee: ₹200
• 60-day total: ₹12,000
• 0.25% cap: ₹25,000 (₹10 crore × 0.25%)

The ₹12,000 late fee is manageable. What causes real damage is a demand notice under Section 73 or Section 74 triggered when GSTR-9 reveals excess ITC claims or understated turnover. Section 73 demands carry 18% interest on tax dues from the original due date, plus a penalty ranging from 10% to 100% of the unpaid tax depending on the nature of default. On a ₹5 lakh ITC excess, a Section 73 demand can crystallise into a liability of ₹7–10 lakh by the time interest and penalty are added.

Section 74 (fraud or wilful misstatement) carries a minimum penalty of 100% of tax dues. While the department must prove intent for Section 74, a pattern of persistent GSTR-2B mismatches and unexplained Table 8D figures can make that case easier to build.

Key Takeaways

• GSTR-9 is mandatory for all regular GST taxpayers with annual turnover above ₹2 crore for FY 2025-26; optional below that threshold.
• GSTR-9C is mandatory only when turnover exceeds ₹5 crore and is now self-certified by the taxpayer — no separate CA certification is required under GST law.
• The due date for FY 2025-26 is December 31, 2026. Start your reconciliation in September, not December.
• Table 8 (ITC vs GSTR-2B) and Part V (previous FY amendments) are the two sections most likely to draw departmental scrutiny.
• Late fees are ₹200 per day capped at 0.25% of turnover, but the real exposure is a Section 73 demand if the return reveals excess ITC claims or suppressed turnover.

How corpus Helps

corpus auto-builds your GSTR-9 working paper from monthly GSTR-1 and GSTR-3B data — no manual aggregation across twelve months of returns. Throughout the year, the platform flags mismatches between GSTR-2B and the ITC booked on purchase bills in real time, so gaps surface when they are easy to fix rather than in December when they are not. For clients above ₹5 crore, the GSTR-9C module maps P&L turnover directly to GST-declared supplies and provides pre-built narration templates for the most common adjustments — exempted supplies, credit notes, and advance receipt reversals. When you are ready to file, corpus generates the JSON upload payload in the exact format the GST portal accepts.

A clean annual return starts with clean monthly bookkeeping. corpus makes that the default, and December deadlines become routine rather than a crisis.