Why ITC Reversal Matters in 2026

Input Tax Credit (ITC) is one of the most powerful features of India’s Goods and Services Tax (GST) framework, allowing registered businesses to offset the tax paid on purchases against the tax collected on sales. However, not all ITC availed is eligible for retention. When a business makes both taxable and exempt supplies, or uses inputs for personal/non-business purposes, a portion of the ITC must be reversed — and this is precisely governed by Rule 42 and Rule 43 of the CGST Rules, 2017.

As of 2026, with the GST Council having issued multiple clarifications and the GSTN portal becoming increasingly sophisticated, ITC reversal under Rule 42 and 43 remains one of the most audit-sensitive areas for Indian businesses. GSTR-9 annual returns now auto-populate ITC reversal data, and mismatches between GSTR-3B and GSTR-9 are triggering scrutiny notices across India.

This comprehensive guide covers every aspect of ITC reversal under Rule 42 and Rule 43 — the legal basis, step-by-step calculation methodology, real-world examples in Indian Rupees, GSTR-3B reporting requirements, annual adjustments in GSTR-9, common mistakes, and the latest 2026 updates from the GST Council and CBIC.

1. Legal Framework: What Are Rule 42 and Rule 43?

Rule 42 and Rule 43 are part of Chapter V (Input Tax Credit) of the CGST Rules, 2017, notified under Section 17(1) and Section 17(2) of the CGST Act, 2017. These rules specify the manner in which ITC must be apportioned when inputs/input services (Rule 42) or capital goods (Rule 43) are used for both taxable and exempt supplies.

The Governing Provisions of CGST Act, 2017

The key sections that make Rules 42 and 43 mandatory are:

What Triggers ITC Reversal?

ITC reversal under these rules is triggered in three main scenarios:

1. The registered person makes both taxable and exempt supplies using the same inputs/capital goods
2. Inputs or services are used partly for personal purposes and partly for business
3. The ratio of exempt to total supplies changes over the financial year (annual adjustment required)

2. Rule 42: ITC Reversal on Inputs and Input Services — Complete Breakdown

Rule 42 applies to inputs (goods) and input services — not capital goods. It mandates a three-step apportionment process every month and an annual reconciliation at the end of the financial year.

Step 1 — Identify T, T1, T2, T3, T4, C1, D1, D2, C2

The Rule 42 formula uses specific notations. Here is what each term means:

Step 2 — The Rule 42 Calculation Formula

Step 3 — Worked Example (FY 2025–26, April 2025 Tax Period)

ABC Pharmaceuticals Pvt. Ltd., Mumbai, deals in both taxable medicines and exempt healthcare services. Their April 2025 ITC position is as follows:

Annual Adjustment at Year-End (Rule 42 Proviso)

At the end of the financial year (before filing GSTR-3B for September or before the annual return filing date, whichever is earlier), the taxpayer must recalculate D1 using the ACTUAL annual turnover figures. If the actual D1 is higher than the sum of monthly D1 amounts, the difference must be added to GSTR-3B as additional reversal. If lower, the excess reversed can be reclaimed as ITC.

For FY 2025–26: If total annual exempt turnover is ₹2.4 crore and total annual turnover is ₹12 crore (ratio 20%), but monthly reversals were computed at 25% average, the business can reclaim the excess reversed ITC in the return for September 2026 or GSTR-9.

3. Rule 43: ITC Reversal on Capital Goods — Complete Breakdown

Rule 43 governs ITC reversal for capital goods — machinery, equipment, furniture, computers, vehicles (where allowed), etc. Capital goods are treated differently because they are used over multiple years and their ITC is spread over a 5-year useful life (60 months) as per the CGST framework.

Categories of Capital Goods under Rule 43

Rule 43 Calculation Methodology

Worked Example — Rule 43 Capital Goods (FY 2025–26)

XYZ Chemicals Ltd., Pune, purchased the following capital goods in FY 2025–26:

Rule 43 Calculation for Common Capital Goods (Office ACs + Forklifts):

Key Differences: Rule 42 vs Rule 43

4. What Qualifies as ‘Exempt Supply’ for Rule 42 & 43 Purposes?

Section 17(3) of CGST Act provides an expanded definition of ‘exempt supply’ specifically for ITC purposes, which is broader than the standard definition under Section 2(47). This wider definition is crucial for correctly computing the exempt ratio in Rule 42 and 43.

Exempt Supply Includes (for Rule 42/43):

• Nil-rated supplies (GST rate = 0%)
• Wholly exempted supplies (notified under Section 11)
• Non-GST supplies (petroleum products, alcohol for human consumption, electricity, etc.)
• Supplies where RCM (Reverse Charge Mechanism) applies on the recipient
• Schedule III activities (transactions treated as neither supply of goods nor services)

What Is NOT Exempt Supply:

• Zero-rated supplies (exports and SEZ supplies) — these are TAXABLE and ITC is fully available
• Supplies under IGST exemption to SEZ developers
• Deemed exports under Section 147

IMPORTANT 2026 Update: The CBIC Circular No. 220/14/2024-GST (and subsequent 2025 circulars) has clarified that interest income from banks by NBFCs and insurance companies must be included in exempt turnover for Rule 42/43 computation, causing significant ITC reversals for financial sector businesses. Taxpayers in BFSI sector must recompute their FY 2024–25 and FY 2025–26 positions accordingly.

5. How to Report ITC Reversal in GSTR-3B, GSTR-9 & GSTR-9C (2026)

GSTR-3B: Monthly/Quarterly Reporting

ITC reversals under Rule 42 and Rule 43 are reported in Table 4(B) of GSTR-3B. From FY 2024–25 onwards, the GSTN portal auto-populates ITC from GSTR-2B, but Rule 42/43 reversals must still be manually entered by the taxpayer.

⚠️ Common 2026 Error: Many taxpayers incorrectly report T2 (exempt-exclusive ITC) in Table 4(B)(1) instead of Table 4(D)(1), creating GSTR-9 mismatches. T2 is not a ‘reversal’ — it is ‘ineligible ITC’ and must go to Table 4(D).

GSTR-9: Annual Return — ITC Reversal Reconciliation

In the GSTR-9 Annual Return, ITC reversal details appear in:

• Table 7A: ITC reversed under Rule 42 and 43 (aggregate for the year)
• Table 7B: Other reversals (blocked credits, etc.)
• Table 7H: Total ITC reversed (auto-calculated)
• Table 12: Reversal of ITC availed during previous FY (if reversal relates to prior year ITC)

The annual adjustment: If your actual annual exempt ratio differs from the monthly averages, the net difference (additional reversal OR reclaim) must be reported in Table 7A of GSTR-9. Due date for GSTR-9 (FY 2025–26): 31 December 2026.

GSTR-9C: Reconciliation Statement

For taxpayers with aggregate turnover exceeding ₹5 crore (self-certified GSTR-9C), Table 14 covers ITC reconciliation, including whether Rule 42/43 reversals have been correctly computed. Auditors flag discrepancies between the proportionate reversal computed theoretically vs what has been actually reversed in GSTR-3B.

6. Sector-Wise ITC Reversal Examples Under Rule 42 & 43 (India 2026)

Example 1: Real Estate Developer (Mumbai)

A builder in Mumbai constructs both residential apartments (exempt under GST if sold before completion; taxable if under construction) and commercial shops. ITC on common construction materials (cement, steel, tiles) and services (architect, contractor) must be apportioned under Rule 42. The exempt ratio is computed as: Value of exempt residential apartments ÷ Total value of all apartments sold.

Example 2: Hospital (Healthcare Provider, Hyderabad)

A multi-specialty hospital provides both exempt healthcare services and taxable services (cafeteria, pharmacy, cosmetic procedures, rooms with rent > ₹5,000/day). Inputs like medicines for exempt treatment vs. medicines sold in pharmacy (taxable) must be tracked. Common inputs (electricity, housekeeping) are subject to Rule 42.

Example 3: Bank / NBFC (New Delhi)

Financial institutions are among the most significantly impacted by Rule 42/43 in 2026. Banks earn both taxable income (locker charges, processing fees, forex services) and exempt income (interest income on loans, which is treated as exempt for GST purposes as per 2024–25 CBIC clarification). The exempt ratio for most banks is 80–95%, meaning only 5–20% of ITC on common inputs (IT systems, office premises, etc.) is eligible.

Example 4: Educational Institution (Bengaluru)

A private university providing both exempt educational courses and taxable services (hostel accommodation > ₹20,000/month, taxable professional courses, canteen with GST) must apply Rule 42 on common inputs like electricity, maintenance, and IT infrastructure.

7. Step-by-Step: How to Reverse ITC on the GSTN Portal (2026)
8. Log in to the GST portal at www.gst.gov.in with your GSTIN and credentials
9. Navigate to: Returns Dashboard → Select Financial Year 2025–26 → Select Month
10. Click ‘Prepare Online’ for GSTR-3B (or ‘File GSTR-3B’ if using offline tool)
11. Go to Table 4 — Eligible ITC
12. In 4(A): Enter total ITC from GSTR-2B (auto-populated from April 2025 onwards)
13. In 4(B)(1): Enter ITC Reversal amount as computed under Rule 42 (D1 + D2) + Rule 43 (Te)
14. In 4(D)(1): Enter ITC that is ineligible due to being exclusively for exempt supplies (T2)
15. In 4(D)(2): Enter blocked credits u/s 17(5) (T4)
16. Net ITC available = 4(A) – 4(B)(1) – 4(B)(2) is auto-calculated
17. Save and proceed to preview; verify ITC reversal matches your Rule 42/43 working sheet
18. File GSTR-3B using DSC or EVC; pay any output tax after ITC offset

💡 Pro Tip: Maintain a separate Excel workbook for Rule 42/43 calculations each month, cross-referenced with your GSTR-2B data. The GSTN portal does not auto-calculate Rule 42/43 reversals — this computation is entirely the taxpayer’s responsibility.

8. Penalties, Interest & Consequences of Non-Compliance (2026)

Failure to reverse ITC as required under Rule 42 and 43 is treated as wrongful availment of ITC under Section 73 or Section 74 of the CGST Act. The consequences in 2026 are:

Impact of Finance Act 2025 on ITC Interest

The Finance Act 2025 (effective April 2025) introduced a nuanced amendment: interest on ITC reversal is now computed on a net basis only where the taxpayer has made excess payment of output tax (i.e., interest runs from the date of wrongful ITC utilization to the date of reversal, not from the return filing date). This change — confirmed by CBIC Circular 2025 — provides relief to taxpayers who discover errors in self-audit.

9. Top 10 Common Mistakes in ITC Reversal Under Rule 42 & 43
10. Not computing Rule 42/43 at all — many small businesses are unaware of this obligation
11. Including zero-rated supply (exports) turnover in exempt turnover — exports are taxable, not exempt
12. Excluding non-GST supplies (petroleum, alcohol, electricity) from exempt turnover — these MUST be included
13. Not doing the annual adjustment — the year-end true-up is mandatory, not optional
14. Computing D2 (personal use) at a flat 5% even when personal use is clearly identifiable — leads to under/over-reversal
15. Treating Rule 42 reversal and blocked credit (Sec 17(5)) as the same — they are reported in different tables
16. Not maintaining a month-wise Rule 42/43 working file — creates audit trail issues during GST scrutiny
17. Using gross turnover instead of aggregate turnover for the exempt ratio — leads to computational errors
18. Ignoring Rule 43 for capital goods purchased before GST registration — transitional issues apply
19. Not filing revised computation in GSTR-9 when annual ratio differs from monthly estimates

10. Key 2026 Updates: GST Council & CBIC Notifications on Rule 42 & 43

11. Best Practices for ITC Reversal Compliance in 2026

• Maintain a dedicated ITC Register (as per Rule 36) with separate columns for T1, T2, T3, T4, C1 every month
• Use accounting software (Tally Prime 5.0+, Zoho Books, or SAP B1) that supports Rule 42/43 auto-computation
• Reconcile GSTR-2B with purchase register before computing C1 to avoid over-claiming ITC
• Conduct a mid-year review (September) to compare actual exempt ratio with monthly estimates — adjust early
• Engage a GST practitioner or CA with specific experience in Rule 42/43 for sectors with high exempt supply
• File GSTR-9 well before 31 December 2026 to allow time for amendments and corrections
• Maintain supplier-wise ITC records to easily segregate T1 (exclusively taxable) vs common credits
• Use the GST portal’s ITC Ledger to verify opening/closing positions and reversal entries

For businesses with aggregate turnover above ₹5 crore, maintaining a formal Rule 42/43 working paper reviewed and certified by a CA before each GSTR-3B filing is recommended — this serves as contemporaneous documentation in case of GST scrutiny or audit.