In short: Tamil Nadu is a Category X state for GST return filing, which means QRMP-scheme GSTR-3B is due on the 22nd, not the 24th. The intra-state e-way bill threshold is Rs 1 lakh, higher than the Rs 50,000 default most states use. The GSTAT Chennai Bench has been hearing appeals since April 2026, so Tamil Nadu businesses no longer need a High Court writ for every GST dispute. And the compliance calendar has moved fast in 2025-26 – new GST 2.0 rates, a reworked Invoice Management System, and a three-year time bar on stale returns have all landed within the last twelve months. CA Murli Chandak, FCA and IBBI-Registered Valuer, helps Chennai businesses register correctly, file on time, protect input tax credit, and respond to notices – with direct access to him, not a rotating desk of articled trainees.
Contents
- GST Registration in Tamil Nadu: Thresholds and What Actually Trips Businesses Up
- Return Filing in Chennai: Monthly Filing vs QRMP, and Why the 22nd Matters
- Input Tax Credit: GSTR-2B, IMS and Where Chennai Businesses Lose Credit
- GST 2.0 and the 2025-26 Changes at a Glance
- E-Way Bill Rules for Tamil Nadu: The Rs 1 Lakh Threshold
- GST and Tamil Nadu’s Economy: Why the Scale Raises the Compliance Bar
- GST Notices, Scrutiny and Departmental Audits
- Appeals and the GSTAT Chennai Bench
- Beyond Compliance: Virtual CFO and ESOP Support for Growing Businesses
- Why Chennai Businesses Work With CA Murli Chandak
- How to Get Started
- Frequently Asked Questions
1. GST Registration in Tamil Nadu: Thresholds and What Actually Trips Businesses Up
Tamil Nadu is a normal-category state under GST, which sets two different registration thresholds depending on what you sell. A business dealing purely in goods must register once aggregate turnover crosses Rs 40 lakh in a financial year. A business supplying services, or a mixed supplier of goods and services, crosses the line at Rs 20 lakh. Both figures are computed on an all-India, same-PAN basis – not per state and not per GSTIN – and include exempt supplies, exports and inter-state supplies, while excluding GST itself and reverse-charge inward supplies.
Where Chennai businesses actually get caught out is rarely the headline threshold. It is the exceptions that override it. Inter-state supply of goods requires registration from the first rupee, with no threshold at all. E-commerce sellers must register regardless of turnover if they sell through a marketplace. A trader who casually assumes “I’m under Rs 40 lakh, I don’t need to register” while shipping even a small consignment to a customer in another state can find themselves liable for tax, interest and a late-registration penalty on everything shipped since the obligation arose.
On the process side, a genuinely useful change landed on 1 November 2025: Rule 14A now allows low-risk applicants – broadly, those whose monthly B2B output tax liability will not exceed Rs 2.5 lakh – to get an auto-approved GSTIN within three working days, bypassing the standard seven-day (or up to thirty-day, where physical verification is triggered) track. It is a meaningful head start for a new Chennai consultancy, boutique manufacturer or professional practice that wants to start invoicing without a month-long wait.
2. Return Filing in Chennai: Monthly Filing vs QRMP, and Why the 22nd Matters
Regular taxpayers file GSTR-1 (outward supplies) by the 11th of the following month and GSTR-3B (summary return and payment) by the 20th, every month. Businesses with aggregate turnover up to Rs 5 crore in the previous year can instead opt into the Quarterly Return Monthly Payment (QRMP) scheme – filing GSTR-1 (or the monthly Invoice Furnishing Facility) by the 13th after the quarter, and GSTR-3B by either the 22nd or the 24th of the month following the quarter, depending on which category their state falls into.
Tamil Nadu is a Category X state, alongside Maharashtra, Karnataka, Gujarat and several others – so QRMP-scheme GSTR-3B in Chennai is due on the 22nd, not the 24th used by Category Y states like Delhi, Uttar Pradesh and West Bengal. It is a small detail, but it is exactly the kind of detail that trips up a business owner who last checked a due-date calendar built for a different state, or a bookkeeper managing GSTINs across multiple states without a state-specific compliance calendar.
QRMP does not mean tax is paid quarterly – only the return is. Tax for the first two months of each quarter is still deposited monthly via Form PMT-06 by the 25th, with the third month’s liability settled when the quarterly GSTR-3B itself is filed. Late fees for GSTR-1 or GSTR-3B are capped by turnover slab – Rs 2,000 for turnover up to Rs 1.5 crore, Rs 5,000 up to Rs 5 crore, and Rs 10,000 above that – while nil returns attract a lighter Rs 20 per day, capped at Rs 500. None of this can be settled using input tax credit; it is a cash payment.
A less forgiving change is now live: returns that remain unfiled for three years past their due date become permanently barred from filing, on a phased rollout that began 1 December 2025. A GSTR-1, GSTR-3B or GSTR-9 that crosses that line cannot be filed at all – not late, not with a penalty, not ever. For any Chennai business sitting on an old backlog, that clock is a genuine reason to close it out now rather than later.
Not sure whether your input tax credit is fully protected under the new IMS rules?
CA Murli Chandak reviews your GSTR-2B reconciliation, flags at-risk credit, and clears the backlog before it turns into a notice.
3. Input Tax Credit: GSTR-2B, IMS and Where Chennai Businesses Lose Credit
Input tax credit is claimed against GSTR-2B, the auto-drafted statement generated from what your suppliers report – not against your purchase register, and not against what you believe you are owed. If a vendor files late, files incorrectly, or does not file at all, the credit simply does not show up in your 2B, whatever your invoice says.
The Invoice Management System (IMS), with its credit-note handling rules tightened from October 2025 under GSTN Advisory 628, adds another layer that Chennai finance teams need to actively manage rather than ignore. Credit notes issued by suppliers now sit in the IMS for the recipient to accept, reject or keep pending – and inaction has consequences for how much ITC eventually flows through to GSTR-3B. A finance team that treats IMS as a once-a-quarter chore, rather than a routine reconciliation task, is the most common way we see genuine, legitimate credit go unclaimed or get reversed.
The other recurring leak is blocked credit under Section 17(5) – on motor vehicles, employee catering, club memberships and similar categories – being claimed anyway because the accounting team is coding purchases by expense head rather than by GST eligibility. It is a basic control, but it is the one that shows up most often in the notices we see.
4. GST 2.0 and the 2025-26 Changes at a Glance
The last twelve months have brought more structural change to GST than any period since its 2017 launch. The table below is the set of changes that matter most to a Chennai business right now.
| Change | Effective | What It Means for You |
|---|---|---|
| GST 2.0 rate rationalisation – four slabs collapsed to 5%, 18% and a 40% de-merit rate | 22 Sept 2025 | Re-check output rates on every product/service line and update pricing, contracts and invoicing masters |
| Rule 14A risk-based registration | 1 Nov 2025 | Low-risk applicants (monthly B2B liability up to Rs 2.5 lakh) can get a GSTIN in 3 working days |
| IMS credit-note acceptance rules tightened (Advisory 628) | Oct 2025 | Act on supplier credit notes in the Invoice Management System promptly, or risk an ITC reversal |
| Three-year time bar on filing GSTR-1, 3B, 9 and other returns | Phased from 1 Dec 2025 | Returns unfiled three years past due date become permanently unfileable – clear old backlogs now |
| E-invoicing: 30-day IRP reporting window | Turnover above Rs 10 crore | E-invoices must be reported to the Invoice Registration Portal within 30 days of issue |
| Permanent GSTR-9 exemption below Rs 2 crore turnover | Ongoing | Smaller Chennai businesses are permanently spared the annual return, not just for one year |
| Second proviso, Section 13(8)(b), IGST Act omitted (Finance Act 2026, s.157) | 30 Mar 2026 | Place-of-supply rule for intermediary services changes; payments to foreign intermediaries may flip toward forward charge |
| GSTAT Chennai Bench operational | 1 Apr 2026 | Tamil Nadu GST appeals can now be heard locally, instead of via a High Court writ |
Always confirm the current due date and notification text on the GST portal before filing or paying – CBIC extensions do happen, and this table reflects the position as of the date of this article.
5. E-Way Bill Rules for Tamil Nadu: The Rs 1 Lakh Threshold
The national default e-way bill threshold is Rs 50,000, for both inter-state and intra-state movement of goods. Tamil Nadu is one of a handful of states – alongside Maharashtra, Delhi, Punjab, Bihar and a few others – that has raised its own intra-state threshold higher, to Rs 1 lakh, effective since 2 June 2018. So a consignment moving entirely within Tamil Nadu – say, from a Chennai warehouse to a dealer in Coimbatore – only needs an e-way bill once its value crosses Rs 1 lakh. The moment any leg of that movement crosses a state border, the standard Rs 50,000 inter-state threshold applies instead.
A small number of goods categories are exempted from the e-way bill requirement altogether under the state notification, regardless of value. Getting this wrong in either direction has real consequences – goods moving without a required e-way bill are liable to detention and penalty at a check point, while generating one unnecessarily just adds friction and cost to routine dispatches.
6. GST and Tamil Nadu’s Economy: Why the Scale Raises the Compliance Bar
Tamil Nadu is India’s second-largest state economy, with a gross state domestic product estimated near Rs 36.67 lakh crore for 2025-26 and GDP growth running around 13.4% for the year – services alone account for roughly 54% of that output, ahead of industry and agriculture. Exports out of the state ran to roughly Rs 5.83 lakh crore in 2024-25. On the GST side specifically, Tamil Nadu has consistently sat among the five highest-collecting states month on month through 2025-26, and its taxpayer base is one of the largest in the country – India crossed roughly 96.8 lakh active GST registrations nationally by August 2026, with Tamil Nadu among the handful of states, alongside Uttar Pradesh, Maharashtra, Gujarat and Karnataka, that account for a disproportionate share of that base.
That scale cuts both ways for a Chennai business. It means a deep, liquid market and a genuinely large pool of GST-registered counterparties to trade with. It also means the state GST administration runs data-matching and scrutiny at a scale that smaller states simply do not see – mismatches between GSTR-1, GSTR-3B and e-way bill data get flagged systematically, not occasionally. A compliance approach that might go unnoticed in a smaller state is far less likely to slip through in Tamil Nadu. Treating GST compliance as a background task rather than an active discipline is a materially bigger risk here than it is elsewhere.
7. GST Notices, Scrutiny and Departmental Audits
Most GST notices in Chennai trace back to one of a small number of triggers: a mismatch between GSTR-1 and GSTR-3B, ITC claimed in GSTR-3B that does not tie back to GSTR-2B, e-way bill values that do not match invoice values, or a refund claim that looks large relative to turnover. Section 61 scrutiny of returns is the most common first step; Section 65 departmental audit and Section 66 special audit go deeper for a smaller number of taxpayers.
Where a genuine shortfall is found, the department proceeds either under Section 73 (short payment or wrong ITC, no fraud alleged) or the considerably harsher Section 74 (fraud, wilful misstatement or suppression of facts), which carries steeper penalties and a longer limitation period. The gap between those two sections is often decided as much by how the response is drafted as by the underlying facts – which is exactly why a rushed, template reply from whoever is available in the accounts team is the wrong way to handle one. A notice under either section has a fixed response window, and missing it converts a defensible position into an ex-parte order.
8. Appeals and the GSTAT Chennai Bench
The first stop for disputing a GST order is still the first appellate authority – the Commissioner (Appeals) – under Section 107, with a three-month filing window plus a further month condonable for sufficient cause. What has genuinely changed for Tamil Nadu is the level above that. The GST Appellate Tribunal’s Chennai Bench had its members assume charge on 22 January 2026, began formally accepting appeals from 1 April 2026, and held its first online hearing on 23 June 2026 – covering appeals from Tamil Nadu and Puducherry, with Madurai as the state’s second bench. Before this, the only route beyond the first appeal was a writ petition to the Madras High Court – slower, costlier, and not designed to be a routine GST appellate forum.
For any Chennai business that has been sitting on an adverse appellate order because a High Court writ felt disproportionate, that calculus has changed. Appeals to GSTAT are filed electronically through the GSTAT e-filing portal, with physical hearings and representation still required at the bench stage.
9. Beyond Compliance: Virtual CFO and ESOP Support for Growing Businesses
GST compliance rarely sits in isolation for a growing Chennai business – it connects directly to pricing, cash flow planning and how equity compensation is structured for a hiring team. CA Murli Chandak also works with Chennai businesses on Virtual CFO services, providing the financial oversight and reporting discipline that a full-time CFO would, without the full-time cost, and on ESOP design and valuation for companies building out equity-based compensation for their teams. Businesses that engage on GST early often find these adjacent gaps – unclear cash flow visibility, an ESOP pool that was never formally valued – surface naturally in the same conversation.
10. Why Chennai Businesses Work With CA Murli Chandak
CA Murli Chandak is a Fellow Chartered Accountant (FCA) with over 8 years of practice, and an IBBI-Registered Valuer for Securities or Financial Assets (IBBI/RV/07/2021/14408). Engagements are handled directly by him, not routed through a rotating bench of articled trainees – when you call with a notice or a filing question, you are speaking to the person who will actually work on it. The practice is built for remote delivery: documents, filings and consultations are handled digitally and over calls, honestly framed as such rather than dressed up with an office address that adds nothing to the quality of the work. Fees are quoted in writing after understanding the scope of what you need – there are no standard published rates, because a single-GSTIN trader and a multi-state services company need genuinely different amounts of work.
11. How to Get Started
A first conversation is free and typically 30 minutes – enough to understand whether you need registration support, a return-filing cleanup, an ITC health check, or help responding to a notice that has already landed. From there, you get a written scope and quotation before any engagement begins, so there are no surprises once work starts.
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12. Frequently Asked Questions
1. What is the GST registration threshold in Tamil Nadu?
Rs 40 lakh aggregate turnover for businesses supplying only goods, and Rs 20 lakh for service providers and mixed suppliers of goods and services, computed on an all-India basis under the same PAN.
2. Is Tamil Nadu a Category X or Category Y state for QRMP?
Category X. Businesses on the QRMP scheme file their quarterly GSTR-3B by the 22nd of the month following the quarter, not the 24th used by Category Y states.
3. What is the e-way bill limit for movement within Tamil Nadu?
Rs 1 lakh for intra-state movement, higher than the national Rs 50,000 default. The standard Rs 50,000 threshold still applies once goods cross into or out of Tamil Nadu.
4. When is GSTR-9 and GSTR-9C due for FY 2025-26?
31 December 2026, in line with the standard annual return timeline, subject to any notified extension. Businesses under Rs 2 crore turnover are permanently exempt from GSTR-9; GSTR-9C applies above Rs 5 crore turnover.
5. What happens if I miss a GST return filing for too long?
Since December 2025, returns unfiled for three years past their due date become permanently barred from filing on the GST portal – not just late, but unfileable. Clearing an old backlog before it crosses that line is now a genuine deadline, not just good practice.
6. How has GST 2.0 changed rates from September 2025?
The GST Council collapsed the earlier four-slab structure into two main slabs – 5% and 18% – with a 40% de-merit rate for select luxury and sin goods, effective 22 September 2025. Most goods previously at 12% moved to 5%, and most goods previously at 28% moved to 18%.
7. What is the Invoice Management System (IMS) and how does it affect my ITC?
IMS is the portal workflow where you accept, reject or hold pending each inward invoice and credit note reported by your suppliers before it flows into your GSTR-2B and, from there, your ITC claim. Credit-note handling was tightened from October 2025 – inaction on a pending credit note can affect how much credit ultimately reaches your return.
8. Where do I appeal a Tamil Nadu GST order now that GSTAT is operational?
After the first appeal to the Commissioner (Appeals) under Section 107, the next stop is the GSTAT Chennai Bench (or the Madurai Bench, depending on jurisdiction), operational since April 2026, rather than a High Court writ petition.
9. Do e-commerce sellers in Chennai need GST registration below the threshold?
Yes. Suppliers selling through e-commerce operators must register under GST regardless of turnover – there is no threshold exemption for this category.
10. Does CA Murli Chandak work with businesses outside Chennai city?
Yes. Engagements are delivered remotely, so businesses anywhere in Tamil Nadu – and outside the state – are served the same way as those based in Chennai.
CA Murli Chandak – FCA | IBBI-Registered Valuer (Securities or Financial Assets) | IBBI/RV/07/2021/14408
Website: murlichandak.com
Phone: +91 99985 39902
Email: murlichandak@murlichandak.com
LinkedIn: CA Murli Chandak
Related reading: Virtual CFO in Chennai | ESOP Consultant in Chennai | Income Tax Consultant in Chennai | About CA Murli Chandak
Disclaimer: This article is for general information only and does not constitute professional advice. GST rates, thresholds, due dates and procedures are subject to change by notification; always verify the current position on the GST portal or with a qualified professional before acting. Accurate as of 3 September 2026.