Input Tax Credit (ITC) Under GST: Complete Guide

Input Tax Credit (ITC) is the backbone of GST — it prevents cascading of taxes by allowing businesses to offset the GST paid on purchases against their output tax liability. But the rules are strict: claim incorrectly, and you face interest, penalties, and demand notices.

This comprehensive guide covers eligibility, conditions, blocked credits, time limits, reversals, and the GSTR-2B matching process.

What is Input Tax Credit (ITC)?

ITC is the credit that a registered person can claim for the GST paid on purchases of goods and services used in the course of business. It reduces your net tax payable:

Net GST Payable = Output Tax − Input Tax Credit

Conditions for Claiming ITC (Section 16)

All four conditions must be satisfied:

1. Possession of tax invoice or debit note from a registered supplier
2. Receipt of goods/services — goods actually received, or services rendered
3. Tax actually paid to government — supplier must have filed return and paid the tax (reflected in your GSTR-2B)
4. Filing of return — you must have filed GSTR-3B to claim the credit

Additional conditions:

• 180-day payment rule: If you don't pay the supplier within 180 days of invoice date, ITC must be reversed with interest. Re-claim only upon payment.
• Depreciation: If you've claimed depreciation on the tax component of a capital good, you cannot claim ITC on it.

GSTR-2B: The ITC Bible

Since January 2022, ITC claims are linked to GSTR-2B — an auto-generated statement showing ITC available to you based on your suppliers' GSTR-1 filings. The rule is:

• ITC in GSTR-3B cannot exceed GSTR-2B available ITC + 5% (from Jan 2022, the 5% tolerance was removed — now it's 100% matching mandatory for B2B credits)
• Any excess claim triggers auto-generated notices
• If your supplier hasn't filed GSTR-1, the invoice won't appear in your GSTR-2B

Blocked Credits — Section 17(5)

ITC is NOT available on these items regardless of business use:

ITC Reversal Rules

Rule 42 — Common Credits (Goods & Services)

When inputs are used for both taxable and exempt supplies:

ITC to reverse = Common ITC × (Exempt turnover ÷ Total turnover)

Rule 43 — Capital Goods

Proportional reversal over 60 months based on exempt turnover ratio each month.

Other Reversal Triggers

• Non-payment to supplier within 180 days
• Goods/services used for non-business or exempt purposes
• Goods lost, stolen, destroyed, or given as free samples
• Supplier's registration cancelled retrospectively

Time Limit for ITC Claims

Section 16(4): ITC must be claimed by the earlier of:

• November 30 following the end of the financial year to which the invoice belongs
• Date of filing annual return (GSTR-9) for that year

Example: Invoice dated March 15, 2026 → ITC must be claimed by November 30, 2026 at the latest.

ITC Set-Off Order

When offsetting ITC against output tax, the mandatory order (post-amendment) is:

1. IGST credit → first against IGST, then CGST, then SGST
2. CGST credit → against CGST, then IGST (NOT against SGST)
3. SGST credit → against SGST, then IGST (NOT against CGST)

ITC Reconciliation Best Practices

1. Download GSTR-2B on the 14th of every month (after suppliers file GSTR-1)
2. Match with your purchase register — identify missing invoices
3. Follow up with suppliers whose invoices aren't appearing
4. Only claim ITC that appears in GSTR-2B (avoid excess claims)
5. Maintain a pending ITC tracker for invoices not yet in GSTR-2B
6. Reconcile yearly before filing GSTR-9 to catch missed credits