What is ASMT-10?
ASMT-10 is a notice of discrepancies in returns issued under Rule 99 of the CGST Rules, 2017 read with Section 61 of the CGST Act, 2017. It is the first formal step of return scrutiny — the proper officer has reviewed your filed returns (GSTR-1, GSTR-3B, GSTR-9, GSTR-2A/2B, e-way bills) and found inconsistencies that, in their view, may indicate short payment of tax, wrong availment of input tax credit (ITC), or incorrect classification.
The notice itself is just a request for explanation — there is no demand at this stage. But it is also the cheapest moment to close the file. If your reply (Form ASMT-11) is accepted, the officer issues ASMT-12 and proceedings are dropped. If it isn't, the file moves to a Show Cause Notice (DRC-01) under Section 73 or 74, where penalty and interest enter the picture.
Why did I get an ASMT-10? Five common reasons
Indian tax departments have substantially automated scrutiny since FY22. ASMT-10 today is largely system-triggered. The five patterns that account for ~85% of notices we see:
- GSTR-3B vs GSTR-1 mismatch (outward supplies) — your declared output tax in GSTR-3B is less than the invoices reported in GSTR-1. Often a timing or amendment issue.
- GSTR-3B vs GSTR-2A/2B mismatch (input tax credit) — you claimed ITC that doesn't appear in 2A/2B because the supplier hasn't filed GSTR-1 or filed it late. The most common notice we see in 2026.
- Inter-state vs intra-state misclassification — IGST vs CGST+SGST split inconsistent with the place-of-supply rules.
- Reverse charge under-payment — Section 9(3)/9(4) liabilities (GTA, import of services, security services, advocate fees) not declared in Table 3.1(d) of GSTR-3B.
- HSN / rate inconsistency — same HSN reported at different rates across periods, or rate slab change not picked up.
For each of these, the officer expects a quantified, document-backed reply — not generic statements. The reply must reconcile your books, the portal data, and the supplier filings.
Time limit and what happens if you miss it
Under Rule 99(2) of the CGST Rules, the registered person shall furnish a reply in Form ASMT-11 within 30 days from the date of service of the notice. The period can be extended on a written request, but extensions are not automatic and rarely granted twice.
If no reply is filed within 30 days, the proper officer is empowered to "initiate appropriate action including the ones under Section 65, 66 or 67, or proceed to determine the tax and other dues under Section 73 or Section 74". In practice, this means a DRC-01 Show Cause Notice with the full alleged demand plus interest and penalty.
How to reply to ASMT-10 — a 4-step framework
Step 1: Reconcile
Before writing a single word, build a reconciliation statement. For an ITC mismatch: pull your purchase register, GSTR-2A, GSTR-2B, and supplier-wise GSTR-1 status. Identify exactly which invoices the officer is questioning. For a 3B-vs-1 mismatch: pull your sales register and identify amendments, credit/debit notes, and timing differences.
Step 2: Categorise the discrepancy
Each line item should fall into one of four buckets: (a) already explained — reverse-charge or amendment captured elsewhere; (b) supplier non-compliance — invoice valid, supplier didn't file; (c) assessee error — needs correction via DRC-03; (d) officer error — wrong period, wrong assessee, double counting. Most notices have a mix of all four.
Step 3: Draft the reply on merits + procedure
Two parallel arguments in every reply:
- On merits: address each line item with proof. For ITC, cite Section 16(2)(a)–(d) compliance, attach payment proofs, supplier ledger.
- On procedure / law: rely on case law that limits the officer's power to disallow ITC for supplier non-compliance, and cite CBIC clarifications.
Step 4: File ASMT-11 on the GST portal
The reply form is available at Services > User Services > My Applications > Form ASMT-10. Upload the PDF reply, the reconciliation working sheet, and supporting invoices. The portal accepts up to 5 attachments of 5 MB each. If you've voluntarily corrected anything, file DRC-03 first and reference its ARN in the reply.
Sample ASMT-10 reply (real structure)
Below is the structure of a Full Reply for a GSTR-3B vs GSTR-2A mismatch case. The full PDF version is 8–11 pages; this is the skeleton.
1. Notice particulars
This reply is filed in Form ASMT-11 under Rule 99(2) of the CGST Rules, 2017, in response to ASMT-10 notice bearing reference no. [ZA0707240003846] issued under Section 61 of the CGST Act, 2017, for the tax period April 2023 to March 2024, alleging a discrepancy of ₹4,20,000 on account of mismatch between input tax credit availed in GSTR-3B and the auto-populated GSTR-2A/2B.
2. Background and reconciliation
The assessee carries on business of [business activity] under GSTIN 19ABCDE1234F1Z5. The alleged mismatch is on account of three suppliers, the details of which are tabulated in Annexure-A to this reply. Of the alleged ₹4,20,000, an amount of ₹2,80,000 represents invoices where the supplier filed GSTR-1 in a subsequent quarter, and ₹1,40,000 represents invoices where supplier-side reconciliation is in progress.
3. Grounds of defence
3.1 The assessee has fulfilled all four conditions of Section 16(2) of the CGST Act — namely, possession of valid tax invoice, receipt of goods, payment of consideration including tax to the supplier, and timely filing of GSTR-3B. Reliance is placed on CBIC Circular No. 183/15/2022-GST dated 27.12.2022, which clarifies the procedure for ITC reconciliation in such mismatches and permits credit on satisfactory documentation.
3.2 Section 16(2)(c) cannot be invoked against the recipient where the supplier has subsequently filed the return and the tax has reached the consolidated fund. This view is supported by the Madras High Court in D.Y. Beathel Enterprises v. State Tax Officer (2021) and by the Calcutta High Court in Suncraft Energy v. Assistant Commissioner (2023), which held that the department must first examine supplier-side default before recovering from the recipient.
3.3 The Hon'ble Supreme Court in Bharti Airtel Ltd. v. UoI recognised that ITC mismatch arising from data-mapping issues on the GSTN portal cannot be a ground for denial where substantive conditions are met.
4. Prayer
In light of the above, your good office is requested to drop the proceedings initiated vide the impugned ASMT-10 notice and issue an acceptance order in Form GST ASMT-12. In the alternative, an opportunity of personal hearing is requested under Section 75(4) of the CGST Act before any adverse order is passed.
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Top 5 grounds of defence with case law
Most ASMT-10 replies fall back on a small set of well-established legal grounds. Knowing which to use, and which not, is the difference between a closed file and a DRC-01.
1. Substantive compliance with Section 16(2)
Argue that all four limbs of Section 16(2) are satisfied. Attach invoice copies, GR/LR for receipt of goods, bank statements for payment, and the GSTR-3B filing acknowledgment. Bharti Airtel Ltd. v. UoI (2021).
2. Supplier non-compliance is not assessee default
The recipient cannot be made to suffer for the supplier's default in filing GSTR-1 or GSTR-3B. D.Y. Beathel Enterprises v. State Tax Officer (Madras HC, 2021); LGW Industries Ltd. v. UoI (Calcutta HC); Suncraft Energy v. Assistant Commissioner (Calcutta HC, 2023).
3. Reliance on CBIC clarifications
CBIC has explicitly addressed many common scrutiny scenarios. Circular 170/02/2022-GST (clarification on furnishing details in GSTR-3B), Circular 183/15/2022-GST (ITC differences for FY 2017-18 and 2018-19), and Circular 193/05/2023-GST (clarification on Rule 36(4)) are all admissible defences when factually applicable.
4. Limitation under Section 73(10) / 74(10)
If the period in dispute is over 3 years old (Section 73) or 5 years old (Section 74) by the relevant due date, raise limitation as a separate ground. Many ASMT-10s for FY 2017-18 issued in 2025 are time-barred unless extended notification applies.
5. Natural justice / personal hearing
Always end the reply with a request for personal hearing under Section 75(4). Department orders without hearing have been quashed by various High Courts including Tvl. Aanmiyan Construction (Madras HC). This is a procedural safety net.
ASMT-10 vs ASMT-11 vs ASMT-12 — what's the difference?
These three forms are stages of the same scrutiny process. Confusing them is the most common mistake we see in DIY replies.
| Form | Who issues | Purpose | Outcome |
|---|---|---|---|
| ASMT-10 | Proper officer | Notice of discrepancies in returns | You must reply within 30 days |
| ASMT-11 | You (the registered person) | Reply to ASMT-10 with explanation + reconciliation | Officer reviews and decides |
| ASMT-12 | Proper officer | Order accepting the explanation | Proceedings dropped — file closed |
If the officer is not satisfied with ASMT-11, the matter does not stop here — it moves to a Show Cause Notice (DRC-01) under Section 73 or 74 of the CGST Act. That is when interest and penalty exposure begins.
Frequently asked questions
Can I reply to ASMT-10 myself, or do I need a CA?
You can reply yourself. The portal allows it. Whether you should depends on the demand: under ₹50,000 and a clean book of accounts, a self-reply is reasonable. Above that — or where ITC reconciliation is involved — a CA-reviewed reply is materially better, because the officer reviewing it gives more weight to a structured, citation-rich response.
Will the officer always issue ASMT-12 after I reply?
No. The officer can also do nothing (in which case the matter goes silent until limitation kicks in), or escalate to DRC-01. ASMT-12 is the formal closure but isn't always issued even when the explanation is accepted. Practically, no DRC-01 within 6 months of your reply usually means it's accepted.
Can I file a revised reply?
The portal does not have a "revise ASMT-11" button. If you discover an error after submitting, file a supplementary letter via the same notice thread on the portal, addressed to the same proper officer, referencing your earlier reply ARN.
What if the discrepancy is genuine and I owe the tax?
Voluntary payment via DRC-03 before filing ASMT-11 is the cheapest closure: tax + interest only, no penalty. Reference the DRC-03 ARN in your ASMT-11 reply. Section 73(8) explicitly bars further proceedings after voluntary payment in scrutiny stage.
How do I know if my notice was served?
Log in to the GST portal and go to Services > User Services > View Notices and Orders. The notice will list the issue date and the service date. The 30-day period runs from the service date.
Replying to a different GST notice?
We cover every common GST notice — same playbook, different statute and grounds.
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