How to claim Input Tax Credit (ITC) in India — a practitioner's step-by-step guide

In my second year of running a services firm in Pune, I skipped one GSTR-2B reconciliation cycle. Six months later, our CA calmly told us we had ₹8.14 lakh of ITC that had lapsed forever. That single mistake pushed our effective tax rate from 18% to 22.6% that year. This guide is everything I've learned since — the rules, the workflow, and the traps I keep watching new businesses fall into.

What is Input Tax Credit, in one paragraph?

When you buy something for your business, the supplier charges you GST on top of the price. When you sell something, you charge GST from your customer. Input Tax Credit (ITC) is the mechanism that lets you subtract the GST you paid on inputs from the GST you collected on outputs, and pay only the difference to the government. Without ITC, GST would cascade — tax on tax — through every stage of the supply chain.

Example: You buy raw material for ₹1,00,000 + ₹18,000 GST = ₹1,18,000. You sell the finished product for ₹1,50,000 + ₹27,000 GST = ₹1,77,000. You keep ₹1,50,000 as revenue, and pay the government ₹27,000 − ₹18,000 = ₹9,000 net.

The four conditions of section 16 — memorise these

Section 16(2) of the CGST Act 2017 says you can claim ITC only if all four are true simultaneously:

1. You possess a valid tax invoice, debit note, or other prescribed document from a GST-registered supplier.
2. You have actually received the goods or services. "Bill and hold" or paper-only invoices don't qualify.
3. The supplier has paid tax to the government (has filed their GSTR-3B).
4. You have filed your own GSTR-3B for the period in which the credit is claimed.

Post-2022 amendments added a fifth practical condition, section 16(2)(aa): the invoice must appear in your GSTR-2B before you can claim ITC. In other words, if your supplier hasn't uploaded the invoice, you cannot claim the credit — even if you possess the paper invoice and have paid them in full.

Step 1 — Set up your books to capture ITC-eligible inputs

Before any monthly cycle, your bookkeeping needs three columns for every purchase:

• Supplier GSTIN
• Invoice number, date, and total
• ITC bucket: CGST / SGST / IGST / cess amounts

If you're using a spreadsheet, add columns for "eligible?" (Y/N — see section 17(5) below), "reverse charge?" (Y/N), and "date of receipt of goods." Miss any of these and month-end reconciliation becomes an archaeology project.

Step 2 — Download GSTR-2B on the 14th of every month

GSTR-2B is the government's authoritative statement of ITC eligibility. It is generated automatically on the 14th of the month following the tax period, based on your suppliers' GSTR-1 submissions. Unlike GSTR-2A (which keeps changing as suppliers file/amend returns), GSTR-2B is static once generated — that's exactly why it's the reference document.

To download: log in to gst.gov.in → Returns Dashboard → Select return period → View / Download GSTR-2B → Export to Excel.

Step 3 — Reconcile GSTR-2B against your purchase register

Match every line in GSTR-2B with a corresponding entry in your books. Four scenarios can happen:

Step 4 — Understand what section 17(5) BLOCKS

Even if all four conditions are met, ITC is blocked on the following categories:

• Motor vehicles for personal use (with narrow exceptions — dealers, drivers' training, passenger transport)
• Food, beverages, outdoor catering, beauty, health, plastic surgery, health insurance (unless mandated by law for staff)
• Membership of clubs, health/fitness centres
• Travel benefits to employees on vacation (leave/home travel concession)
• Rent-a-cab, life insurance, health insurance (with exceptions)
• Works contract services for construction of immovable property (except plant & machinery)
• Goods and services used for personal consumption
• Goods lost, stolen, destroyed, written off, or disposed of as gifts / free samples
• Any tax paid under section 74 (fraud), 129 (detention), or 130 (confiscation)

Flag these categories in your books at the point of purchase — retrofitting the classification during year-end is painful.

Step 5 — Claim ITC in GSTR-3B

In your monthly GSTR-3B (due by the 20th of the following month for most taxpayers), Table 4 is where you declare ITC. Split it into:

• 4(A)(5) — All other ITC (this is the main line)
• 4(A)(3) — ITC on inward supplies liable to reverse charge
• 4(B) — ITC reversal (rules 37, 42, 43 & section 17(5))

The net ITC (A – B) flows to the electronic credit ledger, which offsets your output tax liability.

Step 6 — The 180-day rule

Second proviso to section 16(2) says: if you don't pay the supplier the full invoice amount (including tax) within 180 days of the invoice date, you must reverse the ITC you claimed — with interest. Once you actually pay, you can re-avail the credit. So track your creditor ageing carefully.

Step 7 — The time limit

You must claim ITC on any invoice by the earlier of:

• 30 November of the year following the financial year in which the invoice was issued, OR
• The date you file the annual return (GSTR-9) for that year.

Miss this and the credit lapses forever. This is the exact rule that cost us ₹8.14 lakh.

Reverse Charge Mechanism (RCM) — a special case

Under RCM, you (the recipient) pay GST to the government instead of the supplier. But you can also claim ITC on that same tax — subject to the same section 16 conditions. Common RCM triggers:

• Legal services from an advocate
• Services from a Goods Transport Agency (GTA)
• Import of services
• Sponsorship services to a body corporate
• Director's sitting fees

Workflow: pay GST via cash ledger → issue self-invoice → claim ITC in the same or next month.

Common ITC mistakes we see every quarter

• Claiming ITC on invoices not in GSTR-2B — the #1 audit trigger. Chase suppliers, don't take shortcuts.
• Missing the 180-day payment rule — many businesses claim ITC on credit purchases and forget to reverse when the supplier goes unpaid past 180 days.
• Ignoring section 17(5) blocks — company car ITC, staff insurance ITC, gift ITC all commonly claimed by mistake.
• Waiting till year-end for reconciliation — GSTR-2B has to be matched every month. Waiting three or six months makes chasing suppliers infinitely harder.
• Not tracking place of supply — claiming CGST/SGST on an invoice where the supplier should have charged IGST (or vice versa) leads to disallowance. See our GST calculation guide for how place of supply is determined.
• Composition dealers claiming ITC — they can't. See our bill of supply guide.

The monthly ITC checklist

1. Update purchase register with all invoices received
2. Download GSTR-2B on the 14th
3. Reconcile — match, chase, or adjust
4. Identify section 17(5) blocked credits
5. Compute net eligible ITC
6. File GSTR-3B by the 20th
7. Check creditor ageing — any invoice over 180 days unpaid?
8. Log reversals and re-availments cleanly

Frequently asked questions

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• GST invoice vs tax invoice vs bill of supply
• How to calculate GST on services
• GST slab rates 2026
• 21 small business accounting tips
• GST invoice format — mandatory fields
• GST portal (official)
• CBIC GST notifications