GST Input Tax Credit Denial in 2026: GSTR-2B Mismatch, Supplier Default, Section 16(2)(c), Rule 37A and Re-Availment

By Adv. Govind Bali | Fastrack Legal Solutions LLP
Legally reviewed: 7 September 2026

1. Why ITC Disputes Are a Board-Level Risk

For many businesses, GST input tax credit is not merely a compliance line item. It is embedded in procurement pricing, working-capital assumptions, vendor contracts, EBITDA projections and cash-flow planning. A large ITC reversal can therefore create an immediate balance-sheet and liquidity impact.

Corporate legal and finance teams should treat ITC exposure as a contract-management issue as much as a tax issue. The legal question is not only whether the company received an invoice. It is whether the complete statutory chain can be proved and whether vendor defaults are contractually allocated.

2. The Statutory Starting Point: Section 16

Section 16 of the Central Goods and Services Tax Act, 2017 governs eligibility and conditions for ITC. The current framework requires attention to several cumulative conditions. The recipient must ordinarily possess the prescribed tax document, the supplier must furnish invoice details in the outward-supply statement so they are communicated to the recipient, the recipient must receive the goods or services, the tax charged must actually be paid to Government subject to the statutory mechanism, and the recipient must file the required return.

The official CGST Act is available through India Code. The conditions must be read with Section 41 and the CGST Rules rather than treating Section 16 as a stand-alone invoice test.

3. GSTR-2B: What It Proves and What It Does Not

GSTR-2B is a static statement generated for the recipient from supplier-side filings. In routine corporate compliance, it is the principal reconciliation document against the purchase register and GSTR-3B. If an invoice does not appear, the recipient should identify whether the cause is supplier non-filing, incorrect GSTIN, incorrect period, amendment, credit note, filing delay or another reporting error.

However, appearance in GSTR-2B does not by itself prove every condition under Section 16. Conversely, a historical mismatch may not always justify a mechanical demand without examining the statutory period, amendments, reconciliation evidence and later supplier compliance.

4. Section 16(2)(c): Supplier Payment Is a Statutory Condition

Section 16(2)(c) links recipient credit to actual payment of the corresponding tax to Government, subject to the statutory framework. This is one of the most commercially difficult aspects of GST because the purchaser cannot directly operate the supplier’s electronic cash or credit ledger.

Recent 2026 litigation has brought the issue back into focus. In Shree Karni Electrovision v. Union of India, Rajasthan High Court, 17 August 2026, the Court emphasised the statutory nature of Section 16(2)(c), Section 41 and Rule 37A. The Court noted that recipients can protect themselves through vendor diligence, reversal/re-availment mechanisms and contractual indemnities rather than treating ITC as unconditional merely because tax was paid to the vendor.

5. Section 41 and Rule 37A: Temporary Reversal, Not Always Permanent Loss

The modern GST framework contains a specific mechanism for supplier non-payment. Section 41 provides for availment of eligible ITC subject to conditions, while the rules require reversal where the supplier does not furnish the corresponding return or otherwise does not meet the statutory payment condition within the specified framework.

Rule 37A is particularly important. Where ITC has been availed on an invoice reflected in GSTR-2B but the supplier fails to furnish the return containing the corresponding liability for the relevant period, the recipient may be required to reverse the credit within the prescribed timeline. Once the supplier subsequently complies and the statutory conditions are met, re-availment can become available.

This is why corporate teams should distinguish temporary reversal from final disallowance. The accounting, litigation and vendor-recovery strategies are different.

6. Vendor Default Does Not Eliminate the Need for Due Diligence

A purchaser cannot assume that payment through banking channels alone immunises the ITC claim. The company should maintain evidence of the actual transaction: purchase order, tax invoice, e-way bill where applicable, goods receipt note, delivery challan, transport record, gate entry, stock record, service completion evidence, contract, payment proof and corresponding accounting entries.

Section 155 places the burden of proving ITC eligibility on the person claiming it. A paper invoice unsupported by actual supply evidence is vulnerable even if the supplier once held a valid registration.

7. Retrospective Cancellation of Supplier Registration

A common demand arises when the department later cancels a supplier’s GST registration with retrospective effect and then treats all invoices issued during that period as invalid. Courts have repeatedly examined whether bona fide recipients can be penalised mechanically where actual goods or services, payments and tax documents are proved.

The correct defence is evidence-driven. The recipient should establish what it knew at the transaction date, whether the supplier was shown as registered on the portal, whether the supply was genuine, whether goods moved, whether payments were made through traceable channels and whether there is any allegation of collusion.

In Barun Kumar Biswas v. Union of India, Calcutta High Court proceedings in May 2026 again brought this issue before the Court in the context of retrospective cancellation and ITC denial. The case illustrates why a company should preserve portal-status evidence and supplier-verification records contemporaneously rather than trying to reconstruct them years later.

8. 2026 Rajasthan Decisions and the Statutory Burden

Recent Rajasthan High Court litigation has emphasised that Section 16 conditions remain legally significant even where the recipient claims bona fide conduct. In Sumetco Alloys Pvt. Ltd. v. Union of India, August 2026, the Court examined Section 16, Section 41 and Section 155 in a supplier-default dispute. The important operational lesson is that the recipient should not defend solely on fairness; it must prove statutory compliance and factual genuineness.

Where tax is later recovered from the supplier, re-availment or appropriate consequential relief should be examined rather than accepting double economic loss without review.

9. Retrospective Relief Under Section 16(5)

Finance (No. 2) Act, 2024 inserted Section 16(5) retrospectively from 1 July 2017. For specified invoices or debit notes pertaining to FY 2017-18, 2018-19, 2019-20 and 2020-21, ITC may be available where the return under Section 39 was filed up to 30 November 2021, notwithstanding the ordinary Section 16(4) cut-off.

CBIC Circular No. 237/31/2024-GST dated 15 October 2024 explains the implementation. It is available on the CBIC GST portal.

This relief is narrow. It addresses timing under Section 16(4); it does not cure unrelated defects such as fictitious invoices, non-receipt of supply or another independent eligibility failure.

10. Section 16(6): Relief After Revocation of Cancellation

Section 16(6) addresses cases where a taxpayer’s registration was cancelled and later revoked. Subject to the statutory conditions, it permits ITC in relation to the intervening period where credit was not already time-barred on the date of cancellation and the relevant returns are furnished within the period prescribed after revocation.

This provision is particularly relevant to businesses whose operations were interrupted by cancellation but later restored. It should be examined together with any adjudication orders that denied ITC purely on timing grounds.

11. Existing Orders Based Only on Section 16(4)

CBIC issued a special rectification framework after the retrospective amendments. Where an order under Sections 73, 74, 107 or 108 denied ITC solely because of Section 16(4), the taxpayer should examine whether the notified rectification procedure and Circular No. 237/31/2024-GST apply.

The word solely is important. If the order also found non-receipt of goods, fake invoices, supplier non-existence or another independent defect, the retrospective timing amendment may not eliminate the entire demand.

12. GSTR-2A vs GSTR-2B: Historical Periods Matter

Older disputes often refer to GSTR-2A because the return architecture evolved over time. A company should not apply a 2026 GSTR-2B rule mechanically to FY 2017-18 facts. The applicable statutory provisions, rules and circulars must be identified for the relevant tax period.

For litigation, prepare a year-wise table of the legal regime, invoice status, supplier filing status and recipient credit claim.

13. Rule 36 and Documentary Conditions

Rule 36 specifies documentary requirements for ITC. Depending on the transaction, the tax invoice, debit note, bill of entry or prescribed document must satisfy the applicable requirements. Missing documents should be reconstructed from supplier, transporter, customs or internal ERP records before reply to a show-cause notice.

14. Can the Department Proceed Only Against the Buyer?

Whether the department should first proceed against the supplier depends on the legal issue, facts and statutory period. Courts have taken fact-sensitive approaches, particularly where the purchaser proves genuine transactions and the supplier alone defaulted. But Section 16(2)(c) cannot simply be ignored.

The strongest recipient defence therefore combines: genuine transaction evidence, proof of reasonable vendor verification, GSTR reconciliation, absence of collusion, supplier-side recovery facts, statutory reversal/re-availment provisions and any applicable judicial precedent.

15. ITC and Insolvent Suppliers

If the supplier enters CIRP or liquidation under the Insolvency and Bankruptcy Code, the recipient should immediately assess the GST consequence. Insolvency of the supplier does not automatically convert an otherwise conditional ITC claim into an unconditional one. Procurement contracts should therefore include tax-compliance representations and indemnities that survive termination and insolvency to the extent legally enforceable.

For broader insolvency and corporate-guarantee exposure, see our guide on director and promoter personal guarantees.

16. Contract Clauses Every Corporate Buyer Should Use

A GST-sensitive procurement contract should consider clauses requiring the vendor to:

• maintain valid GST registration;
• issue legally compliant invoices;
• upload invoice details correctly and within time;
• discharge corresponding tax liability;
• rectify GSTR-1 errors promptly;
• reimburse ITC loss, interest, penalty and reasonable defence cost caused by vendor default;
• cooperate in departmental proceedings;
• provide return-filing evidence when reasonably requested; and
• permit set-off or retention against future vendor payments where legally and contractually permissible.

These clauses should be commercially calibrated. An excessive tax holdback can itself damage supply relationships.

17. Monthly GST Reconciliation Protocol

A company should not wait for annual audit. A monthly protocol can classify invoices into matched, missing, amended, supplier-non-filer, blocked-credit and disputed buckets. High-value mismatches should trigger vendor escalation before statutory deadlines expire.

The legal team should receive a monthly exception report where the exposure exceeds an internal threshold.

18. Responding to ASMT-10, DRC-01A or Show-Cause Notice

Do not answer an ITC mismatch notice with only a ledger printout. Build an invoice-level reconciliation containing supplier GSTIN, invoice number/date, taxable value, tax, GSTR-2A/2B status, date reflected, goods/service receipt proof, payment proof, vendor explanation and current compliance status.

If proceedings relate to FY 2024-25 onward, examine the newer Section 74A demand regime. Our existing guide on Section 74A GST show-cause notices addresses that procedure separately.

19. Fraud Allegation vs Reconciliation Error

A mismatch does not automatically prove fraud. Where the department invokes suppression, wilful misstatement or a higher-penalty theory, the reply should separately contest the factual basis of that allegation. A supplier reporting error, timing difference or bona fide reconciliation issue should not be casually equated with collusion.

20. Appeals and Pre-Deposit

If adjudication confirms a demand, Section 107 appeal strategy should be assessed immediately. Limitation, pre-deposit and the exact disputed tax component should be calculated separately for each head. Do not assume that a pending vendor correction will automatically suspend the appeal period.

21. Documents to Preserve

• Purchase order and contract
• Tax invoice/debit note
• GSTR-2B and historical GSTR-2A extracts
• GSTR-3B and purchase register
• E-way bill
• Goods receipt note/gate entry
• Transporter LR and delivery proof
• Stock and inventory records
• Service completion certificate
• Bank payment evidence
• Supplier GST registration status screenshot
• Vendor compliance correspondence
• Vendor GSTR-1/3B evidence where available
• Reversal and re-availment working
• Section 16(5)/(6) eligibility computation

22. Common Corporate Mistakes

• Claiming ITC merely because an invoice exists.
• Failing to reconcile the purchase register with GSTR-2B monthly.
• Ignoring repeated non-filing by a high-value vendor.
• Not preserving goods-receipt or service-delivery evidence.
• Missing Rule 37A reversal timelines.
• Not re-availing credit after the supplier later complies.
• Assuming Section 16(5) cures every historical ITC defect.
• Allowing appeal limitation to expire while waiting for supplier action.

23. Frequently Asked Questions

If an invoice is in GSTR-2B, is ITC guaranteed?

No. GSTR-2B is important but the other statutory conditions under Section 16 must also be met.

If the supplier does not pay GST, do I permanently lose ITC?

Not necessarily in every case. Section 41 and Rule 37A create reversal and re-availment mechanisms where the supplier later complies. The precise facts and tax period matter.

Can I rely on Section 16(5) for old ITC?

For specified FY 2017-18 to 2020-21 invoices where the relevant return was filed up to 30 November 2021, Section 16(5) can cure the Section 16(4) time-bar issue. It does not cure unrelated eligibility defects.

What if the supplier’s registration was cancelled retrospectively?

Challenge should be built around transaction genuineness, portal status at the relevant time, receipt and payment evidence, absence of collusion and the exact legal basis used for denial.

Should my vendor agreement include a GST indemnity?

For material vendors, a calibrated GST-compliance and ITC-loss indemnity is a strong corporate control, subject to commercial negotiation and enforceability.

24. Conclusion

ITC litigation in 2026 is no longer adequately defended by saying that the buyer paid the invoice. Corporate taxpayers need invoice-level evidence, supplier monitoring, statutory reconciliation, Rule 37A controls and contract remedies. At the same time, GST authorities should not treat every mismatch as fraud or every supplier-side defect as proof of a sham purchase without examining the underlying transaction and applicable statutory relief.

The best defence is built before the notice arrives: strong procurement documentation, monthly GSTR-2B reconciliation, vendor escalation and legally drafted tax-allocation clauses.