First, the One Rule That Overrides Everything Else

Do not ignore a GST notice. Ever.

We know that sounds obvious. But you'd be surprised how many businesses receive a notice, feel anxious about it, don't know what to do, and quietly hope it goes away. It doesn't go away. Every notice has a legal deadline, typically 15 to 30 days. Miss it and the officer makes a decision without hearing your side at all. That's called an ex-parte order — and once it's passed, the demand is confirmed, the penalty hits 100%, and your options become limited to a formal appeal: a longer, more expensive, less certain process.

A notice you engage with early almost always resolves. A notice you ignore always escalates. That's the only rule you need to remember before anything else.

So Why Did You Even Get a Notice? The 2026 Reality

Here's something that surprises a lot of business owners: you can get a GST notice even when you've done nothing wrong. Even when you file every month, on time, without fail.

Because in 2026, the GST department isn't just checking whether you filed. It's running your returns through a multi-layer data matching system that cross-references:

• Your GSTR-1 (sales) against your GSTR-3B (summary return) — do your own numbers agree with each other?
• Your ITC claims in GSTR-3B against your GSTR-2B — did you claim more credit than the portal says you're entitled to?
• Your GST turnover against your Income Tax Return — do both show the same revenue?
• Your e-invoices against what you declared in GSTR-1 — does the e-invoice data match?
• Your e-way bill records against your declared supplies — did goods actually move in line with what you reported?
• Your IMS actions against what you claimed

Any flag across any of these — even a rounding difference, even a supplier filing their invoice a month late — can trigger a notice. The system is automated and doesn't know the context. A notice doesn't mean the department thinks you're a fraudster. It means a number caught their attention and they want an explanation.

The Notice You're Most Likely to Get First: ASMT-10

ASMT-10 is a scrutiny notice issued under Section 61 of the CGST Act. It's the most common GST notice businesses receive, and it's the least scary of the lot — if you handle it properly.

Here's the most important thing to understand about ASMT-10: it is not a demand for money. The officer hasn't decided you owe anything yet. They've spotted a discrepancy and they want your explanation. Think of it as someone from the department saying, "Your GSTR-1 says you sold X, but your GSTR-3B says Y. Can you explain that?"

Your job is to explain it clearly, with documents. That's it.

You respond in Form ASMT-11 within 30 days (extendable by 15 days). Your reply should walk through each discrepancy, explain why it happened — a timing issue, an amended invoice, a supplier error that was later corrected — and back it up with reconciliation statements and invoices.

If the officer is satisfied, they issue ASMT-12. Case closed, no penalty, no demand. If your reply is weak, incomplete, or doesn't address the specific discrepancies raised, the case escalates — which is exactly what you don't want.

DRC-01A: The Warning Shot Most Businesses Miss

This one doesn't get enough attention, and that's a shame — because it's your best opportunity to resolve a situation cheaply.

DRC-01A is a pre-show cause notice intimation. The officer believes there's a tax shortfall but hasn't formally initiated demand proceedings yet. They're essentially giving you a heads-up: "We think you owe money. Here's your chance to deal with this before it gets official."

There's no rigid statutory deadline for DRC-01A, but respond within 7 to 15 days. Why? Because if you pay the tax and interest voluntarily at this stage (through DRC-03), your penalty can be as low as 15% of the demand amount — a very significant saving compared to what happens if you wait.

Businesses that take DRC-01A seriously often resolve the entire matter here with no formal SCN, no adjudication, no appeal. Businesses that ignore it get a DRC-01.

DRC-01: Now It's Officially Serious

DRC-01 is the formal Show Cause Notice. The department is no longer asking — they're initiating demand proceedings. Tax, interest, and penalty are all on the table now, and the clock matters a great deal.

A big change from FY 2024-25 onwards that you need to know about: GST notices for FY 2024-25 and later are now issued under Section 74A, a unified provision that replaced the old split between Section 73 (non-fraud) and Section 74 (fraud). Under 74A, the department has a 42-month window to issue notices, and you have a 60-day window after receiving the SCN during which voluntary payment meaningfully reduces your penalty.

For older financial years (up to FY 2023-24), the old rules still apply — Section 73 for non-fraud (penalty capped at 10%) and Section 74 for fraud or suppression (penalty up to 100%).

The penalty ladder is steep and works against delay:

You respond to DRC-01 in Form DRC-06 within 30 days. A proper reply here, with reconciliations, invoices, and a well-argued legal position, can result in the demand being dropped or significantly reduced. A hasty or poorly prepared reply locks in the demand.

GSTR-3A: The Non-Filing Notice

This is the most straightforward one. If you haven't filed GSTR-1 or GSTR-3B for one or more periods, the system auto-generates a GSTR-3A notice and gives you 15 days to file the pending returns.

The fix is obvious: file the returns. But don't rush and file something wrong. A return that's filed incorrectly creates a whole new problem on top of the original delay. Take an extra day, match your data properly, confirm your ITC against GSTR-2B, and file clean.

REG-03 and REG-17: When Your Registration Is at Risk

REG-03 comes up during a fresh GST registration — the officer needs additional documents or clarification before approving your registration. Respond in 7 working days with whatever they've asked for. It's usually procedural and resolvable.

REG-17 is a different matter entirely. This is a show cause notice for cancellation of your existing GST registration. It can be triggered by persistent non-filing, mismatches in your registration details, the new 2026 automated rule that flags bank account name mismatches against your GSTIN, or suspected fake registration activity.

Respond in Form REG-18 within 7 working days. If your registration gets cancelled and you don't act fast to revoke it, you lose the ability to issue valid GST invoices. For any business doing B2B sales, that's an operational shutdown. Treat REG-17 as an emergency.

The Escalation Ladder. What Happens at Each Step

Here's the sequence so you can see exactly where any notice can go if you don't engage:

Every stage up this ladder is more expensive than the one before. Every stage up this ladder also narrows what you can do. The best move is always to engage at the earliest possible point.

What Ignoring a Notice Actually Costs You

Let's put a number to what "ignoring it" looks like on a ₹5 lakh demand:

Plus, if recovery proceedings are initiated, the department can attach your bank account — which means your business operations can freeze while this gets sorted. That's a cost that doesn't even show up in the penalty numbers.

How to Actually Respond to a Notice: The Practical Steps

When to Handle It Yourself vs. When to Get a CA

Be honest about this assessment.

The logic here is simple. A poorly drafted reply to a DRC-01 that concedes an argument you could have won, or misses a legal defence, can lock in a demand of ₹5 lakh, ₹10 lakh, or more. A CA's fee to draft the reply is a fraction of that. The downside risk of handling it badly is the demand itself.