Input Tax Credit (ITC) Explained: What I Watch at Our Mill

What Input Tax Credit Is

Every business in a GST chain charges GST on what it sells (output tax) and pays GST on what it buys (input tax). Input tax credit lets you subtract the input tax from the output tax and pay only the difference to the government.

Without ITC, tax would pile on tax at every stage: the manufacturer's tax, the wholesaler's tax on top of that, the retailer's tax on top of that, and the final price would balloon. ITC breaks that cascade so that, across the whole chain, tax is effectively charged once on the final value.

A one-line definition to keep: ITC is the GST you already paid on business inputs, which you set off against the GST you owe on your sales.

The Four Conditions That Must All Hold

You cannot claim ITC just because you spent money and have a receipt. All four of the following must be true:

1. You hold a valid tax invoice (or debit note / prescribed document) from a registered supplier, showing the GST charged.
2. You have actually received the goods or services. You cannot claim credit on something you have only ordered.
3. The credit appears in your GSTR-2B, the auto-drafted statement generated from your suppliers' filings. If your supplier has not filed their GSTR-1, the credit will not appear, and you cannot claim it that period.
4. The supplier has actually paid the tax to the government. If they collected GST from you but never deposited it, your credit can be denied.

Condition 3 is the one that trips up small businesses, because it depends on someone else's behaviour. Your supplier files GSTR-1, your invoice flows into your GSTR-2B, and only then is the credit available to you. This is why GSTR-2B is, in practice, your ITC dashboard, and why you reconcile against it before filing GSTR-3B.

GSTR-2B: Your ITC Source of Truth

GSTR-2B is a read-only statement, generated automatically each month (typically around the 14th, for the previous period), listing every input tax credit available to you based on what your suppliers filed. You cannot edit it. The discipline is simple: claim only what shows in GSTR-2B.

To use it:

1. Log in to gst.gov.in.
2. Go to Services → Returns → Auto Drafted ITC Statement (GSTR-2B).
3. Select the period and download the PDF or Excel.
4. Match it against your own purchase register (every invoice you received from registered suppliers).

When you reconcile, you will hit three cases:

• Invoice in your records but not in GSTR-2B: the supplier has not filed yet. You cannot claim this period; chase the supplier and claim once it appears.
• Credit in GSTR-2B but not in your records: a purchase you forgot to record, or a wrong entry by the supplier. Investigate before relying on it.
• Both match: claim it.

Claiming ITC that is not backed by GSTR-2B is the fastest way to a demand notice and an interest bill. A GST tracker with a GSTR-2B match flag on every purchase line turns this into a monthly tick-box instead of a year-end hunt.

If you would rather not do this matching by hand every month, I made the GST ITC Reconciler, my own Google Sheets template that pairs your purchase register with the statement even when suppliers write invoice numbers differently, and lists the suppliers to chase. It's ₹1,999 on Gumroad.

A Pune Furniture Maker's Net GST for the Month

Say a small furniture-making business in Pune (Maharashtra) has this month:

Sales (output tax):

• It sells furniture worth ₹6,00,000 at 18% GST.
• Output GST collected = ₹1,08,000 (₹54,000 CGST + ₹54,000 SGST).

Purchases (input tax) within Maharashtra:

• Timber and raw material: ₹2,50,000 + 18% GST = ₹45,000 GST.
• Workshop tools and equipment: ₹40,000 + 18% GST = ₹7,200 GST.
• Accounting software subscription: ₹10,000 + 18% GST = ₹1,800 GST.

All three suppliers filed their GSTR-1, so the full ₹54,000 of input GST (₹45,000 + ₹7,200 + ₹1,800) appears in the workshop's GSTR-2B.

Its net GST liability:

• Total output GST: ₹1,08,000
• Less ITC available in GSTR-2B: ₹54,000
• Net GST payable when filing GSTR-3B: ₹54,000.

Now suppose the timber supplier had not filed its GSTR-1 that month. The ₹45,000 credit would not appear in GSTR-2B, so the workshop could claim only ₹9,000 (₹7,200 + ₹1,800). Its net payable would jump to ₹99,000 for the month, even though the ₹45,000 was actually paid. It would claim that ₹45,000 in a later month once the supplier files. The cash-flow hit is temporary, but it is real, and it is caused entirely by the supplier's delay. This is the practical reason to prefer suppliers who file on time.

You can sanity-check these splits quickly with a GST calculator before you file.

The 180-Day Rule

If you claim ITC on a purchase, you must pay the supplier the full invoice value (including the GST) within 180 days of the invoice date. If you do not, you must reverse the credit you claimed and pay interest on it. Once you eventually pay the supplier, you can reclaim the credit.

The rule prevents businesses from claiming credit on invoices they never actually settle. It does not apply to reverse-charge supplies. For a business that stretches its payables, this is a real trap: you can lose the credit on bills you have been sitting on. Track invoice ages, for example in a payables tracker, and clear GST-bearing purchases inside the window.

At our mill the pressure often runs the other way. We often pay farmers and suppliers on tighter terms than we can give our own buyers, so the clock I watch hardest is not the 180 days on our payables but the days our receivables stay out.

Where ITC Is Blocked

Even when all four conditions are met, ITC is not allowed on certain items (often called "blocked credits"). The main ones small businesses encounter:

The practical takeaway: just because you have a tax invoice does not mean the credit is claimable. Personal expenses run through the business, the company car, the client dinner: these are common places where owners wrongly claim ITC and create a future problem.

Apportioning ITC Between Business and Other Use

If a purchase is used partly for taxable business supplies and partly for exempt supplies or personal use, you can only claim the proportion relating to your taxable business activity. For example, a phone used 70% for business and 30% personally should have its ITC apportioned accordingly. Mixed-use assets and common expenses (like office rent in a business that has both taxable and exempt income) need this proportional treatment. Keeping business and personal spending cleanly separated, as covered in our guide to separating business and personal finances, makes this far easier and keeps your claims defensible.

How ITC Is Set Off: The Order of Utilisation

Once you have valid ITC, you cannot apply it to any tax head you like in any order. There is a prescribed sequence, and getting it wrong leads to paying more cash than necessary. GST has three components: IGST (inter-state), CGST, and SGST (both intra-state). The set-off rules, in plain terms:

1. IGST credit must be used first against IGST liability. Whatever IGST credit remains can then go against CGST and SGST in any order (Rule 88A of the CGST Rules, in force since 2019). CGST or SGST credit can be used only after the IGST credit has been used up.
2. CGST credit can be used against CGST and then IGST, but never against SGST.
3. SGST credit can be used against SGST and then IGST, but never against CGST.

The most important rule to remember is the last one: CGST and SGST credits cannot be cross-utilised. If you have surplus CGST credit but an SGST liability, you cannot offset one against the other: you pay the SGST in cash and the CGST credit stays in your ledger. This is why a business with lots of inter-state sales (IGST liability) and intra-state purchases (CGST/SGST credit) can sometimes find credit accumulating in one head while paying cash in another.

For most small intra-state businesses this is straightforward: your CGST credit covers your CGST liability and your SGST credit covers your SGST liability. But the moment you have a mix of inter-state and intra-state activity, the order of utilisation starts to affect how much actual cash you part with each month. Accounting software applies the correct order automatically; if you file manually, follow the sequence carefully on the portal.

ITC on Capital Goods

When you buy capital goods (machinery, equipment, computers, furniture used in the business), you can generally claim the full ITC in the period you receive them, provided the four conditions are met and the item is not a blocked credit. There is one catch worth knowing: you cannot both claim ITC and claim depreciation on the GST component under the Income Tax Act for the same amount. You choose one. In practice, most businesses claim the ITC (immediate, full credit) and compute income-tax depreciation only on the base cost excluding GST. Claiming depreciation on the tax portion and taking ITC is not allowed and is a common oversight when the GST and income-tax sides of the books are handled by different people.

That split is exactly how our mill works, with the accountant on the GST records and the CA on finalisation and tax, which is why I would want every capital purchase looked at from both sides before the year closes. The income-tax side of the same purchase is covered in depreciation and fixed assets.

If a capital asset is later sold, or if it was used partly for exempt or personal purposes, a proportional reversal of the credit may apply. Keep capital-goods purchases clearly tagged in your records so these adjustments are easy to track.

The Deadline Nobody Diarises

ITC for a financial year cannot be taken after 30 November following the end of that year, or after you file the annual return for that year, whichever is earlier (Section 16(4) of the CGST Act). An invoice you forgot to claim, a supplier who filed late, a credit you parked and never came back to: once that date passes, the credit is gone for good.

This is the part of ITC I think small businesses underrate. Most of the rules above cost you timing; this one costs you the money. A parked credit needs a date written next to it, and someone who looks at the list before November.

Where ITC Claims Go Wrong

• Claiming on the invoice alone, before it shows in GSTR-2B. The invoice is necessary but not sufficient. Reconcile first.
• Cross-utilising CGST against SGST (or vice versa). Not allowed. Follow the prescribed set-off order or you will misstate your cash payment.
• Claiming both ITC and income-tax depreciation on the GST portion of a capital asset. Choose one, not both.
• Not reconciling purchases against GSTR-2B before filing GSTR-3B. This is where mismatches and notices originate.
• Claiming ITC on blocked items: the company car, client meals, personal expenses, health insurance. Easy to do, expensive to defend.
• Ignoring the 180-day rule. Unpaid GST-bearing invoices can force a credit reversal with interest.
• Buying from non-filing suppliers and assuming the credit will appear. If they do not file, your money is stuck as a deferred (or lost) credit.
• Not apportioning mixed-use purchases. Claiming 100% ITC on something used partly personally invites disallowance.
• Forgetting the time limit to claim. A year's credit cannot be taken after 30 November of the following year, or the annual return if you file it earlier. Missing it means the credit lapses permanently.

A Monthly ITC Checklist

A checklist to keep your ITC clean:

• Maintain a purchase register listing every GST-bearing invoice: supplier GSTIN, invoice number, date, taxable value, and tax.
• Each month, download GSTR-2B from gst.gov.in and reconcile it against that register.
• One common practice is to treat what appears in GSTR-2B as the reference point, and to chase suppliers whose invoices are missing.
• Blocked credits and non-eligible personal spends are the kind of items worth flagging in your records before filing time.
• Track invoice ages; clear GST-bearing supplier payments within 180 days.
• The mixed business/personal purchases in your register are typically the ones where apportionment becomes relevant.
• Prefer suppliers with a track record of timely GST filing; it directly protects your cash flow.
• Keep a list of parked credits with the 30 November cut-off next to each, and sanity-check your splits with a GST calculator before each GSTR-3B.

For personal tax or legal decisions, consult a qualified professional.

Input tax credit rewards the disciplined and punishes the careless. A clean purchase register, monthly reconciliation against GSTR-2B, awareness of blocked credits, and paying suppliers on time are the habits that let ITC do what it is meant to do: tax only the value you add. Treated loosely, it becomes the part of GST most likely to cost you money you already paid, and in my view that is the one GST loss a business has no excuse for.