Last updated: 26 July 2026. Input Tax Credit is the mechanism that stops GST from taxing the same value twice — you pay tax on your purchases, and you set that off against the tax you collect on your sales. But ITC is not a right you get simply because you hold an invoice. It is an entitlement that arrives with strings attached, and those strings are in Section 16 of the CGST Act, 2017. Miss one, and the credit is either delayed, reversed, or lost. Here is what every claim has to clear.
Applicability Note: This guide reflects GST provisions in force as of 26 July 2026. Section 16 has been amended several times — clauses (aa) and (ba) and sub-sections (5) and (6) were all added after 2017. Always verify the current position on gst.gov.in or with a GST professional before filing.
Who Should Care?
- Every registered business claiming ITC — the conditions apply to each invoice, not to your return as a whole.
- Anyone whose GSTR-2B does not match their purchase register — a mismatch now blocks the claim, it does not just flag it.
- Businesses with slow-paying accounts — the 180-day rule can claw back credit you have already used.
- Anyone sitting on old credits — the Section 16(4) clock for FY 2025-26 runs out on 30 November 2026.
1. The Entitlement, and the Override
Section 16(1) gives the entitlement: a registered person can take credit of input tax on goods or services used, or intended to be used, in the course or furtherance of business. That credit lands in the electronic credit ledger.
Then Section 16(2) takes most of it back — provisionally. It opens with "Notwithstanding anything contained in this section, no registered person shall be entitled to the credit of any input tax … unless" a list of conditions is satisfied. That single word, notwithstanding, is why Section 16(2) is where every ITC dispute actually lives: the entitlement in 16(1) means nothing until the conditions in 16(2) are met.
2. The Conditions in Section 16(2)
The statute is usually summarised as "four conditions" — invoice, receipt, tax paid, return filed. That was true in 2017. Two more clauses have since been inserted that tie your credit to what your supplier actually does, so it is really six sub-clauses now:
| # | Condition | Clause |
|---|---|---|
| 1 | You hold a valid tax invoice or debit note from a registered supplier (or other prescribed document) | Sec 16(2)(a) |
| 2 | The supplier has reported that invoice in its GSTR-1, so it is communicated to you | Sec 16(2)(aa) |
| 3 | The credit is not restricted in your GSTR-2B (the auto-generated statement under Section 38) | Sec 16(2)(ba) |
| 4 | You have received the goods or services | Sec 16(2)(b) |
| 5 | The tax has actually been paid to the Government | Sec 16(2)(c) |
| 6 | You have filed your return under Section 39 (GSTR-3B) | Sec 16(2)(d) |
Clauses (aa) and (ba): your credit now depends on your supplier
The two additions changed ITC from a self-declared claim into a matched one. Clause (aa) (effective 1 January 2022) says the invoice must be furnished by the supplier in its GSTR-1 and communicated to you — in practice, it must appear in your GSTR-2B. Clause (ba) (effective 1 October 2022) adds that the credit must not be one that Section 38 flags as restricted. If a supplier forgets to file, files late, or files wrong, your legitimate credit does not show up — and you cannot claim it until it does. This is why reconciling GSTR-2B against your purchase register before you file has stopped being good hygiene and become a hard gate.
Clause (b): "received" includes bill-to/ship-to
Condition (b) is receipt of the goods or services. The Explanation to Section 16(2) adds a deeming fiction: where goods are delivered to a third person on your direction — the classic bill-to/ship-to — you are deemed to have received them. So you do not lose ITC merely because the goods went straight to your customer or your job-worker instead of your own godown.
Clause (c): the tax must reach the government
Condition (c) requires the tax charged on your purchase to have been actually paid to the Government. This is the condition behind years of litigation: a genuine buyer can be denied ITC because a defaulting supplier collected the tax but never deposited it. Rule 37A operationalises part of this — if the supplier has not paid the tax by 30 September following the year of the invoice, the recipient must reverse the credit.
3. The 180-Day Payment Rule
Even after you have validly taken the credit, there is a string attached. The second proviso to Section 16(2) says that if you do not pay your supplier the value of the supply plus the tax within 180 days of the invoice date, you must add back the ITC you availed to your output tax liability — with interest. The mechanics are in Rule 37.
The third proviso softens it: once you actually pay the supplier, you can re-avail the credit — and this re-availment is not subject to the Section 16(4) time limit. So the 180-day rule is a timing and cash-flow trap, not a permanent loss, provided you eventually pay.
Example. You buy services worth ₹1,00,000 + ₹18,000 GST on 1 April 2026 and claim the ₹18,000 credit. By late September 2026 — 180 days later — you still have not paid the vendor. In your next GSTR-3B you must reverse ₹18,000 and pay interest. When you finally settle the invoice in, say, December, you take the ₹18,000 back.
4. The Deadline: Section 16(4)
ITC does not stay claimable forever. Section 16(4) says credit on any invoice or debit note cannot be taken after the earlier of:
- 30 November following the end of the financial year the invoice relates to, or
- the date you furnish the annual return for that year.
For invoices dated in FY 2025-26, that outer limit is 30 November 2026 — meaning the credit must be claimed in a return filed up to the October 2026 GSTR-3B (filed in November), or by the annual return date if you file that earlier. Miss it, and the credit is gone. This is the single most common way businesses permanently lose ITC: an invoice surfaces during a year-end reconciliation, but the November deadline has already passed.
The retrospective relief in 16(5) and 16(6)
Years of ITC were denied purely on this time-bar, much of it under dispute. The Finance (No. 2) Act, 2024 inserted Sections 16(5) and 16(6) retrospectively (with effect from 1 July 2017):
- Section 16(5): for FY 2017-18 to FY 2020-21, ITC is treated as validly availed if the return was filed up to 30 November 2021 — overriding the stricter 16(4) dates that applied then.
- Section 16(6): restores the limitation window for taxpayers whose registration was cancelled and later revoked.
CBIC Circular No. 237/31/2024-GST dated 15 October 2024 tells officers to give effect to this relief in pending matters. One catch: it expressly provides no refund where the tax or ITC was already reversed or paid on account of the old time-bar. The relief helps open disputes; it does not reopen closed ones.
5. What Section 16 Does Not Cover: Blocked Credits
Even if you clear every condition in Section 16, some credits are simply off-limits. Section 17(5) lists blocked credits — motor vehicles (with exceptions), food and beverages, membership of clubs, works contract for immovable property, goods lost or given as free samples, and more. Passing the Section 16 tests does not unblock a Section 17(5) item; they are two separate gates, and a claim must clear both.
6. Mistakes That Keep Recurring
- Claiming from the purchase register, not GSTR-2B. Since clauses (aa) and (ba), the credit that shows in 2B is your ceiling. Book what your supplier reported, then chase the difference.
- Forgetting the 180-day clock. Unpaid vendor invoices quietly become reversals with interest. Track ageing, not just the initial claim.
- Missing the 30 November window. A late-surfacing invoice for the previous FY is worthless after that date — there is no extension for oversight.
- Assuming Section 16 clearance means the credit is allowed. Section 17(5) can still block it. Check both.
Key Takeaways
- ITC is an entitlement under Section 16(1) that only survives if the conditions in Section 16(2) are met — a non-obstante override.
- The classic four — invoice, receipt, tax paid, return filed — are now six, because (aa) and (ba) tie your credit to your supplier's GSTR-1 and your GSTR-2B.
- Pay your supplier within 180 days or reverse the credit with interest (second proviso, Rule 37); re-avail on payment.
- Claim ITC for FY 2025-26 by 30 November 2026 under Section 16(4), or the annual return date if earlier.
- Sections 16(5)/(6) gave retrospective relief for FY 2017-18 to 2020-21 (returns filed up to 30 November 2021), but with no refund of amounts already reversed.
- Clearing Section 16 is not enough — Section 17(5) blocked credits are a separate bar.
Frequently Asked Questions
What are the conditions to claim Input Tax Credit under GST?
Under Section 16(2) of the CGST Act you must hold a valid tax invoice or debit note (clause a), the invoice must be reported by your supplier and communicated to you (clause aa), the credit must not be restricted in your GSTR-2B (clause ba), you must have received the goods or services (clause b), the tax must have actually been paid to the Government (clause c), and you must have filed your return under Section 39 (clause d). All must be satisfied for each invoice.
Can I claim ITC if the invoice is not in my GSTR-2B?
No. Since clause (aa) took effect on 1 January 2022 and clause (ba) on 1 October 2022, ITC can only be availed to the extent the invoice is furnished by your supplier and reflected — not restricted — in your GSTR-2B. If the invoice is missing, follow up with the supplier to report or correct it; you can claim the credit in the period it appears, subject to the Section 16(4) time limit.
What is the 180-day rule for ITC?
Under the second proviso to Section 16(2), if you do not pay your supplier the invoice value plus tax within 180 days of the invoice date, you must add the ITC you claimed back to your output tax liability along with interest (Rule 37). You can re-avail the credit once you make the payment, and that re-availment is not restricted by the Section 16(4) deadline.
What is the last date to claim ITC for FY 2025-26?
Section 16(4) sets the limit at the earlier of 30 November 2026 or the date you file the FY 2025-26 annual return. In practice this means claiming the credit up to the October 2026 GSTR-3B (filed in November 2026), unless you file the annual return sooner.
Do Sections 16(5) and 16(6) extend my current ITC deadline?
No. They are retrospective relief for past years — Section 16(5) validates ITC for FY 2017-18 to 2020-21 where the return was filed up to 30 November 2021, and Section 16(6) helps taxpayers whose registration was cancelled and later revoked. They do not change the ongoing Section 16(4) deadline for current years, and CBIC Circular No. 237/31/2024-GST dated 15 October 2024 confirms no refund is due where tax or ITC was already reversed.
If I meet all Section 16 conditions, is my ITC definitely allowed?
Not necessarily. Section 16 governs eligibility and conditions, but Section 17(5) separately blocks credit on specified items — such as certain motor vehicles, food and beverages, and works contracts for immovable property. A claim must clear both Section 16 and Section 17(5).
Disclaimer: This article is for informational purposes only and does not constitute professional tax advice. GST rules are subject to frequent changes through notifications and circulars. Please consult a qualified tax professional or verify the current provisions on the official GST portal (gst.gov.in) before making any compliance decisions.
Not sure whether an invoice qualifies, or whether the 180-day clock has started on an unpaid vendor? Our GST experts can help → gstconsultancy.com