Input Tax Credit Under GST: Rules, Restrictions, and Common Mistakes

Input tax credit is what keeps GST from becoming a tax-on-tax at every stage of a supply chain — you only pay tax on the value you add, because the GST already paid on your purchases is set off against what you collect on sales. In practice, though, ITC is also where most GST scrutiny notices originate. Businesses claim credit they aren't actually entitled to, sometimes through a genuine misreading of the rules, and sometimes because their accounting software claims whatever sits on a purchase invoice without checking anything else against it. A single blocked or unmatched claim rarely sinks a business on its own, but a pattern of them is exactly what turns a routine desk review into a full audit. Here's what the law actually requires before that credit is yours to use.

The Four Conditions the Law Actually Requires

Section 16 of the CGST Act lays out what has to be true before you can claim ITC on a purchase, and every condition has to hold at once, not just one or two of them. You need a valid tax invoice or debit note from the supplier. You must have actually received the goods or services — not merely placed the order or been billed for them. The supplier must have actually paid that tax to the government by filing their own return, with the corresponding invoice showing up in your GSTR-2B. And you must have filed your own GST return for that period before the credit can be used. Say a supplier bills you ₹1,00,000 plus ₹18,000 GST — until you've received the goods, the supplier has filed and paid, and it shows up in your 2B, that ₹18,000 sitting on the invoice is not yet credit you can use. There's a practical fifth condition tied to timing: if you don't pay your supplier the full invoice value within 180 days of the invoice date, you have to reverse whatever credit you claimed, with interest, and can only reclaim it once you actually pay.

GSTR-2B Is the Final Word, Not a Suggestion

GSTR-2B is an auto-drafted, static statement generated once a month, compiling every invoice your suppliers have reported through their own GSTR-1 or the Invoice Furnishing Facility for that period. The rule today is strict: you can only claim ITC to the extent it actually appears in your GSTR-2B for that period or an earlier one. The older practice of claiming a provisional top-up beyond whatever showed up in supplier data — allowed for a while under a tolerance rule — no longer exists; it has been nil tolerance for a few years now. If a supplier is late filing their GSTR-1, hasn't filed it at all, or has quoted your GSTIN incorrectly, that invoice simply won't appear in your 2B, and the credit isn't available to you yet, no matter how genuine the underlying purchase was. This is exactly why chasing vendors about their own filing discipline has quietly become part of routine accounts payable work rather than something only the tax team worries about.

Credits That Are Permanently Blocked

• Motor vehicles used to transport persons, unless used for further supply of such vehicles, passenger transport as a business, driving instruction, or goods transport
• Food and beverages, outdoor catering, health club and fitness memberships, and cosmetic or plastic surgery, unless the same category of expense is used to make a further taxable supply or the employer is legally obligated to provide it
• Life and health insurance, with the same exceptions — obligatory under law, or used to make a further outward supply of the same category
• Works contract services for constructing an immovable property, except where it's for plant and machinery or the output itself is a further works contract supply
• Goods or services used for personal consumption, and goods that are lost, stolen, destroyed, written off, or given away as gifts or free samples
• Tax paid as a result of fraud, wilful misstatement, or confiscation proceedings — credit is denied on tax paid under those specific demand orders

Where Businesses Actually Go Wrong

The scrutiny cases that come up most often aren't exotic. One very common mistake is claiming ITC that was never reflected in GSTR-2B in the first place, simply because the accountant worked off the purchase register instead of cross-checking the 2B statement before filing. Another is forgetting to reverse credit on invoices left unpaid beyond 180 days, which quietly accumulates into a real liability with interest by the time anyone notices it. A third is claiming full credit on expenses that are only partly for business use — a vehicle or a phone bill used for both business and personal purposes — without doing the proportionate reversal that the law actually requires for mixed-use inputs. A fourth, common around year-end, is claiming credit after the statutory cut-off: ITC for a financial year can only be claimed up to 30th November of the following year, or the date of filing the annual return, whichever comes first, after which it lapses for good regardless of how valid the invoice was.

The GST system now runs an automated check between what you claim in GSTR-3B and what actually shows up in GSTR-2B; if your claim runs ahead of your 2B by more than a small tolerance, an intimation lands in Form DRC-01C and you get about seven days to explain the gap or pay it back. Ignoring it can block your ability to file returns for the following period. Treating ITC as something you reconcile every single month — matching the purchase register against 2B, chasing vendors who haven't filed, tracking the 180-day payment clock — costs far less than untangling that notice after the fact. A little discipline in the filing month beats a lot of explaining a year later.