Input Tax Credit Under GST: Complete Guide for Indian Businesses

Input Tax Credit Explained with an Example

Let's look at an example to help us better understand Input Tax Credit:

'A' purchased goods and services worth ₹30,000, on which the GST rate is 18%, i.e., ₹5,400. Thus, the total amount paid by 'A' would be ₹35,400, out of which ₹5,400 will be paid as GST. Later, 'A' sells the product for ₹40,000, and again the GST rate is 18%, which comes to ₹7,200. This ₹7,200 is due to the Government.

However, since the Government has already received ₹5,400 as GST from 'A', he is now liable to pay only the difference amount, which is ₹1,800. The ₹5,400 that A has already paid while purchasing the goods and services can be claimed by him as Input Tax Credit.

Rule 86B: The 1% Cash Payment Requirement

Rule 86B of the CGST Rules, 2017 (inserted via Notification 94/2020-CT, effective 1 January 2021) restricts the use of ITC for certain high-turnover businesses.

Who it applies to: Registered persons whose aggregate taxable supplies in a month exceed ₹50 lakh (excluding exempt supplies, zero-rated supplies, and supplies under RCM).

What it requires: Such taxpayers must pay at least 1% of their output tax liability in cash through the electronic cash ledger. The remaining 99% can be settled using ITC.

Exceptions - Rule 86B does NOT apply if:

For most tax-compliant SMEs with a regular income tax filing record, Rule 86B will not apply due to the income tax exception. However, businesses that primarily rely on ITC to offset output tax should verify applicability every month.

ITC Utilisation Order: Which Credit Sets Off Which Liability?

One of the most frequently misunderstood mechanics of GST is the mandatory sequence for applying ITC against output tax. This order is governed by Sections 49, 49A, and 49B of the CGST Act, 2017, and cannot be altered at the taxpayer's discretion.

Key rules to remember:

• IGST credit is the most flexible - it can be applied against IGST, CGST, and SGST/UTGST liabilities, in that order.
• CGST and SGST credits cannot cross-offset each other - CGST credit cannot reduce SGST liability and vice versa.
• This sequence is enforced automatically by the GSTN portal when filing GSTR-3B.

Worked example:
A Delhi-based business has the following balances in a given month:

Step 1: Apply IGST credit against IGST liability - ₹20,000 − ₹15,000 = ₹5,000 IGST credit remaining.
Step 2: Apply remaining IGST credit against CGST liability - CGST liability ₹6,000 − ₹5,000 = ₹1,000 CGST still payable.
Step 3: Apply CGST credit against remaining CGST - ₹8,000 available, ₹1,000 used. ₹7,000 CGST credit remains.
Step 4: Apply SGST credit against SGST liability - ₹5,000 credit, ₹6,000 liability. ₹1,000 SGST must be paid in cash.

What are Blocked Credits? - Section 17(5) of the CGST Act

Under Section 17(5) of the CGST Act, certain goods and services are specifically blocked from ITC even if they are used in the course of business, unless a stated exception applies. Some of the most important blocked-credit areas include specified motor vehicles; certain food and beverage expenses; certain health and insurance expenses; club memberships; works contract and construction-related credits in specified cases; personal consumption; and goods lost, stolen, destroyed, written off, or disposed of as gifts or free samples.

The following categories of goods and services are ineligible for ITC:

Businesses should check the current wording of Section 17(5) and relevant CBIC clarifications before taking a position on blocked credit, especially in grey areas involving vehicles, employee-related expenses, construction, and special industry use cases.

Practical note: GSTR-2B is an important reconciliation tool, but it should not be treated as a final legal test of ITC eligibility. Businesses must still independently check whether a credit is blocked under Section 17(5) or requires reversal under Rules 42 or 43.

How to Reverse ITC in GSTR-3B - Table 4 Mapping

When ITC must be reversed , the reversal is reported in Table 4 of GSTR-3B. Different scenarios map to specific rows:

ITC reclaim after 180-day reversal:
If you reversed ITC because a supplier remained unpaid beyond 180 days and later made the payment, you are entitled to reclaim the reversed ITC. Report the reclaimed amount in Table 4(A)(5) - All Other ITC. Crucially, you must also report this same amount in Table 4(D)(1) - ITC Reclaimed to ensure it matches the Electronic Credit Reversal and Reclaimed Statement (ECRS) ledger on the GST portal.

Step-by-step: reversing ITC for a 180-day default

• Identify invoices for which the 180-day payment deadline (from the invoice date) has passed without payment. GST accounting software like BUSY automatically flags invoices approaching the 180-day deadline, so reversals are never missed.
• Calculate the ITC originally claimed on those invoices.
• In GSTR-3B for the month in which the 180-day period expires, add the ITC amount to Table 4(B)(2).
• The reversal increases net tax payable - pay the differential from your cash ledger or available ITC balance.
•  If ITC is reversed under the 180-day rule, businesses should carefully review the applicable interest position before filing, as it should not be stated loosely without current legal validation.
• Once payment is made to the supplier, reclaim the ITC in the month of payment via Table 4(A)(5).

Step 1: Download your GSTR-2B statement
Log in to the GST portal . Navigate to Services → Returns → GSTR-2B. Download the auto-populated statement for the relevant month in Excel format. GSTR-2B is finalised on the 14th of the following month and does not change thereafter.

Step 2: Export your purchase register from your accounting software
Generate a purchase register from your accounting software for the same month. The export should include: supplier GSTIN, invoice number, invoice date, taxable value, IGST, CGST, SGST, and total invoice amount.

Step 3: Match invoice by invoice
Compare each entry in your purchase register against the GSTR-2B. Classify every invoice into one of three categories:

Step 4: Investigate and resolve mismatches
Mismatches occur when an invoice appears in both records but with different values. Common causes include supplier amendments in GSTR-1, invoice number format differences, and unrecorded credit notes. For each mismatch, determine whether your books or the supplier's GSTR-1 is correct, and adjust before filing.

Step 5: File GSTR-3B based on reconciled figures
Report only GSTR-2B-supported ITC in Table 4(A) of GSTR-3B . Invoices not yet reflected in GSTR-2B should be reviewed carefully before claim. Return-table reporting should follow the latest GSTR-3B instructions and CBIC guidance rather than a blanket rule. Once the supplier files and the amount appears in a future GSTR-2B, you can reclaim the ITC in that period through Table 4(A)(5).

BUSY tip: If your software supports GSTR-2B reconciliation , use it to compare supplier invoices with your purchase register and identify matched, unmatched, and mismatched entries before filing. Needs product validation before making any automation claim.

ITC on Imported Goods and Services

Businesses that import goods or services into India are entitled to claim ITC on the taxes paid at import, subject to the standard conditions under Section 16 of the CGST Act.

ITC on Import of Goods

When goods are imported, Integrated Goods and Services Tax (IGST) is levied at the point of customs clearance in addition to Basic Customs Duty (BCD). The BCD is not eligible for ITC, but the IGST paid at customs is fully eligible as ITC.

The import must be for business purposes. Goods imported for personal consumption are blocked under Section 17(5)(g).

ITC for Exporters and Zero-Rated Supplies

Exports and supplies to Special Economic Zones (SEZs) are zero-rated supplies under Section 16 of the IGST Act, 2017 - GST is charged at 0% on the outward supply. However, businesses continue to pay GST on their inputs. This accumulated ITC can be claimed as a cash refund rather than simply offset against output liability.

Exporters generally use one of two routes, subject to the applicable conditions and refund restrictions:

Option 1: Export Under Bond / Letter of Undertaking (LUT)

The exporter pays no IGST on the export transaction by furnishing a Letter of Undertaking (LUT) in Form GST RFD-11. ITC accumulates on inputs (raw materials, packing, freight, etc.) and is claimed as a cash refund under Rule 89 of the CGST Rules.

Refund formula: Refund Amount = (Turnover of Zero-rated Supply × Net ITC) ÷ Adjusted Total Turnover

The refund application is filed in Form GST RFD-01 on the GST portal within 2 years from the relevant date (typically the date of export).

Option 2: Export on payment of IGST and claim refund, where this route is available under the applicable rules and conditions

The exporter pays IGST on the export invoice at the applicable rate. The IGST paid on exports can then be claimed as a direct refund - this is processed automatically based on GSTR-1 (shipping bill linkage) and GSTR-3B data.

SEZ supplies follow the same rules - supplies to SEZ units and SEZ developers are zero-rated and eligible for the same refund mechanism.

Important: Export ITC refunds are processed separately from normal ITC credits. Delays in shipping bill matching on the ICEGATE portal can delay refund processing by 30-90 days. Ensure your shipping bills are correctly linked to your GSTR-1 invoice data.