Input Tax Credit (ITC) Rules Under GST 2026

Input Tax Credit (ITC) is the backbone of the GST system. It allows registered taxpayers to reduce their GST liability by the amount of tax already paid on purchases used for business purposes. Understanding ITC rules is essential for maintaining healthy cash flow, avoiding compliance issues, and ensuring you are not leaving legitimate credits unclaimed.

This comprehensive guide covers everything about ITC under GST for FY 2026-27, including eligibility conditions, the complete list of blocked credits under Section 17(5), reversal rules, GSTR-2B reconciliation procedures, and practical tips to maximise your ITC claims legally.

What Is Input Tax Credit (ITC)?

Input Tax Credit is the mechanism under GST that allows you to claim credit for the GST paid on inputs (raw materials, goods), input services, and capital goods used in the course or furtherance of your business. The credit is set off against the GST liability on your outward supplies (sales), effectively ensuring that tax is levied only on the value added at each stage of the supply chain.

For example, if you are a manufacturer who paid Rs 18,000 as GST on raw materials and collected Rs 36,000 as GST on finished goods, you pay only the difference of Rs 18,000 to the government. The Rs 18,000 you paid on inputs is your Input Tax Credit.

How ITC Flows Through the GST System

The ITC mechanism works through an interconnected chain of returns. When your supplier files their GSTR-1, the invoice details auto-populate your GSTR-2B statement. You verify these details and claim the eligible ITC in your GSTR-3B return. This creates a transparent, verifiable credit chain across the entire supply network.

Eligibility Conditions for Claiming ITC

To successfully claim ITC, you must satisfy all of the following conditions under Section 16 of the CGST Act. Failure to meet even one condition can result in the credit being denied or reversed.

1. Possession of a Valid Tax Invoice or Debit Note

You must hold a tax invoice issued by the supplier under Section 31, or a debit note, that contains all mandatory fields including supplier GSTIN, invoice number, date, HSN code, taxable value, and tax amounts broken down by CGST, SGST, and IGST.

2. Receipt of Goods or Services

ITC can only be claimed after you have actually received the goods or services. For goods delivered in instalments, ITC is available upon receipt of the last instalment. For services, the provision or completion of the service triggers eligibility.

3. Supplier Has Filed Their Return and Paid Tax

The supplier must have filed their GSTR-1 (so the invoice appears in your GSTR-2B) and paid the tax to the government. If the supplier defaults on filing or payment, the ITC claimed by you may be subject to reversal.

4. Invoice Reflected in GSTR-2B

ITC is now restricted to the amount auto-populated in your GSTR-2B statement. The earlier rule allowing 5% provisional ITC over GSTR-2B has been removed. This makes GSTR-2B reconciliation critically important for every business.

5. Payment Made Within 180 Days

The value of the supply including GST must be paid to the supplier within 180 days from the date of the invoice. If not paid within this period, the ITC must be reversed with interest at 18% per annum. It can be re-availed once payment is made.

6. Time Limit for Claiming ITC

ITC for any financial year must be claimed by the earlier of the due date of filing the September GSTR-3B return of the following financial year, or the date of filing the annual return (GSTR-9). For FY 2026-27, this means the deadline is around October 2027 (September 2027 GSTR-3B due date).

7. GST Return Must Be Filed

ITC can only be utilised by filing the relevant GSTR-3B return. If your returns are pending, the ITC remains in your electronic credit ledger but cannot be used to offset liability.

Blocked Credits Under Section 17(5)

Certain goods and services are permanently ineligible for ITC under Section 17(5) of the CGST Act, regardless of whether they are used for business purposes. Understanding this list is crucial to avoid claiming credits that will be denied and attract interest and penalties.

Complete List of Blocked Credits

ITC Reversal Rules

Even after you have legitimately claimed ITC, certain events require you to reverse (repay) the credit. Understanding these rules helps you avoid surprise liability and interest charges.

Rule 42: Reversal for Common Credits (Taxable + Exempt Supplies)

When inputs or input services are used partly for taxable supplies and partly for exempt supplies (or non-business purposes), the ITC attributable to exempt supplies and personal use must be reversed. The calculation under Rule 42 follows these steps:

1. Identify common credits (C2): Total ITC minus ITC exclusively for taxable supplies (T) minus ITC exclusively for exempt supplies (already ineligible).
2. Calculate exempt proportion (D1): (Exempt turnover / Total turnover) multiplied by C2.
3. Calculate personal use proportion (D2): ITC attributable to non-business/personal use.
4. Reverse D1 + D2: This is the amount to be added back to output tax liability in your GSTR-3B.

This calculation must be done monthly based on estimated figures, with an annual true-up at the end of the financial year.

Rule 43: Reversal for Capital Goods

For capital goods used for both taxable and exempt supplies, the reversal is calculated differently. ITC is spread over 60 months (the useful life of the capital good), and for each tax period, the proportionate credit attributable to exempt supplies is reversed.

The formula: ITC per month = Total ITC on capital good / 60. Amount to reverse each month = ITC per month x (Exempt turnover / Total turnover).

180-Day Payment Rule

Under the second proviso to Section 16(2), if payment for the supply (including the tax portion) is not made to the supplier within 180 days from the invoice date, the ITC claimed must be reversed. The reversal must be done in the return for the month immediately following the expiry of 180 days, along with interest at 18% per annum from the date of availing credit to the date of reversal.

The credit can be re-availed once the actual payment is made to the supplier.

Reversal on Account of Credit Notes

When a supplier issues a credit note against a previously issued invoice, the corresponding ITC must be reduced in the period in which the credit note is received. This applies to both quantity returns and price reductions.

Reversal on Change of Business Use

If goods on which ITC was claimed are subsequently used for exempt supplies, exported without payment of tax, or used for non-business purposes, the ITC must be reversed. Conversely, if exempt goods are later used for taxable supplies, ITC can be claimed through the re-availment provisions.

GSTR-2B Reconciliation: The Key to Accurate ITC Claims

Since ITC is now restricted to the amount reflected in GSTR-2B, reconciliation between your purchase register and the GSTR-2B statement is the single most important compliance activity for protecting your ITC claims.

What Is GSTR-2B?

GSTR-2B is an auto-generated, static statement available on the 14th of every month. It shows the ITC available to you based on the GSTR-1, GSTR-5 (non-resident), and GSTR-6 (ISD) filed by your suppliers. Unlike the dynamic GSTR-2A, GSTR-2B is fixed for a given period and serves as the basis for ITC claims in your GSTR-3B.

Step-by-Step Reconciliation Process

1. Download GSTR-2B: Log in to the GST portal and download the GSTR-2B JSON or Excel file for the relevant month.
2. Download your purchase register: Export your books of accounts or accounting software data for the same period, with invoice-level detail including supplier GSTIN, invoice number, date, and tax amounts.
3. Match invoices: Compare each invoice in your purchase register against the GSTR-2B statement. Categorize discrepancies into: matched, in books but not in GSTR-2B, in GSTR-2B but not in books, and amount mismatches.
4. Investigate discrepancies:
   • In books but not in GSTR-2B: The supplier has not filed their GSTR-1 or reported the invoice. Follow up with the supplier to file or correct their return.
   • In GSTR-2B but not in books: Check if the invoice was missed in your books. Record it if valid, or mark it as not your purchase (possible wrong GSTIN entry by supplier).
   • Amount mismatch: Identify whether the difference is in taxable value or tax amount, and coordinate with the supplier for correction.
5. Claim only matched + GSTR-2B eligible ITC: In your GSTR-3B, claim only the ITC that appears in GSTR-2B and matches your books. Unmatched ITC should be deferred until the supplier corrects their filing.

Common Reconciliation Issues

• Supplier delay in filing GSTR-1: If a supplier files their GSTR-1 late, the invoice will appear in a later month's GSTR-2B. You can claim the ITC in the month it finally appears, subject to the annual time limit.
• GSTIN errors by supplier: If a supplier enters a wrong GSTIN, the invoice flows into another party's GSTR-2B. Request the supplier to issue an amendment in their next GSTR-1.
• Duplicate invoices: Sometimes the same invoice appears twice due to amendments. Identify and exclude duplicates from your ITC claim.
• Rate differences: If the supplier reports a different tax rate than what was invoiced, the ITC available will differ. Resolve the correct rate and request correction.

ITC Utilisation Order

When offsetting your GST liability using ITC, the order of utilisation is prescribed by law and must be followed. Getting this wrong can lead to wrong credit entries and compliance issues.

Special ITC Scenarios

ITC on Imports

IGST paid on imports of goods is available as ITC based on the Bill of Entry. The ITC appears in GSTR-2B based on data from the ICEGATE system. Ensure the importer GSTIN is correctly mentioned in the Bill of Entry to receive the credit.

ITC Under Reverse Charge Mechanism (RCM)

When you pay GST under the reverse charge mechanism (for example, on legal services, GTA services, or imports of services), the tax paid is available as ITC in the same month, provided you report it in GSTR-3B Table 3.1(d) and claim ITC in Table 4. RCM ITC is not subject to the GSTR-2B restriction since you are both the payer and the recipient.

ITC for Input Service Distributor (ISD)

If your business has multiple GST registrations and receives services at a centralised office, the ISD mechanism allows distribution of ITC to the respective branches. The ISD must file GSTR-6 to distribute the credit, and the receiving branch claims it through their GSTR-2B.

ITC on Capital Goods

Unlike inputs and input services where ITC is claimed in full upon receipt, capital goods ITC is also available in full at the time of receipt (not spread over the useful life). However, if capital goods are later sold or used for exempt supplies, the proportionate ITC must be reversed using the Rule 43 formula.

Practical Tips to Maximise Your ITC Claims

• Reconcile monthly: Do not wait until the annual return to reconcile. Monthly reconciliation catches issues early and gives suppliers time to correct their GSTR-1.
• Maintain a supplier compliance score: Track which suppliers consistently file on time and which ones cause ITC delays. Address chronic defaulters by requesting advance invoices or switching suppliers.
• Use accounting software with GSTR-2B integration: Tools that automatically download and match GSTR-2B data save significant time and reduce errors.
• Pay suppliers within 180 days: Set up payment tracking to ensure no invoice crosses the 180-day threshold, which triggers mandatory ITC reversal with interest.
• Separate personal and business expenses: Maintain clear boundaries between personal and business purchases to avoid claiming ITC on personal consumption, which is blocked.
• Review blocked credit list regularly: Before claiming ITC on any new type of expense, check it against the Section 17(5) blocked credit list to avoid claiming ineligible credits.
• Claim ITC on RCM promptly: Reverse charge ITC is self-assessed and not dependent on supplier filings. Claim it in the same month to improve cash flow.
• File returns on time: Late filing delays ITC utilisation and may result in interest on the tax paid late. Timely filing keeps your credit ledger active.

Frequently Asked Questions