Rule 42 and Rule 43 of CGST Rules: How to Avoid GST Notices on Proportionate ITC Reversal

1. Introduction

One common mistake that I have noticed during GST return filing is non-compliance with Rule 42 and Rule 43 of the CGST Rules, 2017. This issue generally arises where goods, services or capital goods are used partly for taxable supplies and partly for exempt supplies, or partly for business purposes and partly for non-business purposes.

In such cases, the registered person cannot retain the entire Input Tax Credit. The credit attributable to exempt supplies or non-business use is required to be reversed on a proportionate basis. Due to non-compliance with these provisions, many taxpayers receive notices from the GST Department requiring them to reverse ITC proportionately, along with applicable interest and penalty consequences.

Input Tax Credit is one of the most important benefits available under the GST law, but it is not an unrestricted benefit. Where common inputs, input services or capital goods are used for mixed purposes, proportionate reversal becomes mandatory under Rule 42 and Rule 43 of the Central Goods and Services Tax Rules, 2017.

Rule 42 applies to inputs and input services, whereas Rule 43 applies to capital goods. These rules are based on Section 17(1) and Section 17(2) of the CGST Act, 2017. Section 17(1) restricts ITC to the portion attributable to business purposes, while Section 17(2) restricts ITC to the portion attributable to taxable supplies, including zero-rated supplies.

Therefore, Rule 42 and Rule 43 should not be treated as mere procedural provisions. They are important compliance provisions for every registered person having taxable as well as exempt supplies, or common use of inward supplies for business and non-business purposes.

In this article, I have explained the practical applicability, calculation method, reporting requirement and key precautions relating to Rule 42 and Rule 43. If, after reading this article, you have any doubt or feel that any practical point requires further discussion, you may contact me at the contact details mentioned at the end of this article.

2. Statutory Background

3. Why Rule 42 and Rule 43 Are Important

Many businesses have both taxable and exempt activities. For example, a registered person may have taxable sales along with exempt outward supplies, non-taxable supplies, sale of land / building, interest income , exempt education / healthcare activities, liquor sales, securities transactions, or other mixed activities.

In such cases, common expenses such as rent, audit fees, professional fees, office expenses, security charges, software expenses, repairs and maintenance, electricity-related expenses, consultancy charges and administrative costs may relate to both taxable and exempt activities.

The GST law does not permit full ITC on such common expenditure. The portion attributable to taxable supplies is eligible, while the portion attributable to exempt supplies or non-business use is required to be reversed.

4. Difference Between Rule 42 and Rule 43

Part A - Rule 42: ITC Reversal on Inputs and Input Services

5. Applicability of Rule 42

Rule 42 applies where inputs or input services are used in any of the following manners:

The most important point is that Rule 42 does not require reversal on total ITC . First, the credit has to be classified into eligible, ineligible and common credit . Only the common credit is subjected to proportionate reversal.

6. Step-by-Step Formula under Rule 42

The calculation is as follows:

Where:

Further, D2 = 5% of C2 , where common inputs or input services are used partly for business and partly for non-business purposes.

7. Example of Rule 42 Calculation

Assume the following figures for a tax period:

Step 1: Calculate C1

Step 2: Calculate common credit C2

Step 3: Calculate D1

Step 4: Calculate D2

Total reversal under Rule 42

Thus, Rs. 60,000 is required to be reversed / added to output tax liability through the appropriate GST return mechanism.

8. Annual Final Adjustment under Rule 42

Rule 42 requires monthly reversal on a provisional basis. Thereafter, final calculation is required to be made for the whole financial year.

The annual final calculation must be completed before the due date of furnishing the return for the month of September following the end of the financial year .

This annual finalisation is one of the most common areas of departmental objection during GST audit.

Part B - Rule 43: ITC Reversal on Capital Goods

9. Applicability of Rule 43

Rule 43 applies where capital goods are used in any of the following manners:

Rule 43 treats the useful life of capital goods as five years from the date of invoice, i.e., 60 months .

10. Formula under Rule 43

The broad formula is:

Where:

The amount of Te is required to be added to the output tax liability for every tax period during the useful life of the capital goods.

11. Example of Rule 43 Calculation

Assume the following:

Step 1: Monthly common capital goods credit

Step 2: Exempt turnover ratio

Step 3: ITC reversal for the month

Thus, Rs. 400 is required to be reversed / added to output tax liability for that month. This exercise continues during the useful life of the capital goods.

Part C - Meaning of Exempt Supply for Rule 42 and Rule 43

12. Exempt Supply Must Be Carefully Identified

For Rule 42 and Rule 43 , exempt supply is not limited only to normal exempt outward supply. Section 17(3) expands the value of exempt supply for ITC reversal purposes.

The following may be relevant while computing exempt supply:

However, all non-GST receipts should not be mechanically treated as exempt turnover . Each receipt must be tested under the Act and the relevant rule.

13. Important Exclusions from Exempt Turnover

Rule 42 and Rule 43 contain important exclusions while computing aggregate value of exempt supplies.

This classification is very important because wrong inclusion of turnover in E directly increases ITC reversal .

Part D - Reporting in GSTR-3B

14. Correct Reporting of Rule 42 and Rule 43 Reversal

CBIC Circular No. 170/02/2022-GST clarifies that reversal of ITC under Rule 42 , Rule 43 , Rule 38 and ineligible ITC under Section 17(5) should be reported in Table 4(B)(1) of GSTR-3B.

Temporary or reclaimable reversals are to be reported separately in Table 4(B)(2) .

A common mistake is to report Rule 42 / Rule 43 reversal in Table 4(D) . That is not the correct reporting method where actual reversal is required. Rule 42 / Rule 43 reversal is a non-reclaimable reversal and should ordinarily be reported in Table 4(B)(1) .

Part E - Important Points to Keep in Mind

15. Rule 42 / 43 Apply Only When Section 17 Is Triggered

Rule 42 and Rule 43 apply only where Section 17(1) or Section 17(2) is attracted.

16. Reversal Must Be Computed Only on Common Credit

A frequent mistake is to compute reversal on total ITC . This is incorrect .

The registered person must first segregate ITC into:

Only the common credit is subjected to proportionate reversal.

17. Zero-Rated Supply Is Not Exempt Supply

Exports and supplies to SEZ are zero-rated supplies . They are not exempt supplies for ITC reversal purposes. Therefore, ITC cannot be reversed merely because outward supplies are exports or zero-rated supplies .

This is an important defence point in cases where the department mechanically treats all non-tax-paid outward supplies as exempt.

18. Reversal Must Be Computed Tax-Head-Wise

Rule 42 and Rule 43 calculations should be made separately for the following tax components:

A single consolidated reversal figure without tax-head-wise breakup may create reconciliation issues in GSTR-3B, electronic credit ledger, audit proceedings and annual return.

19. Previous Turnover May Be Used Where Current Turnover Is Not Available

Where there is no turnover in a particular tax period, or the relevant turnover details are not available, the ratio E / F may be determined by taking the turnover of the last tax period for which such details are available, in accordance with the rule.

This point is useful in businesses having seasonal turnover , project-based revenue or intermittent exempt supplies.

20. Blocked Credit under Section 17(5) Is Separate

Blocked credit under Section 17(5) must be identified separately. It should not be mixed with common credit .

Under Rule 42 , blocked credit is removed as T3 before arriving at common credit. Therefore, the correct sequence is:

1. Identify total ITC.

2. Remove non-business ITC.

3. Remove exempt-use ITC.

4. Remove blocked credit.

5. Identify taxable exclusive ITC.

6. Apply Rule 42 formula only on common credit.

21. Real Estate Sector Has Special Project-Wise Rules

In construction / real estate cases covered by paragraph 5(b) of Schedule II , Rule 42 and Rule 43 contain special project-wise provisions. In such cases, the normal turnover-based approach may not always apply in the same manner, and the calculation may be linked to project-specific data such as carpet area, booking status, completion certificate, first occupation and other real estate -specific parameters.

Therefore, real estate cases should not be handled through a simple general Rule 42 / Rule 43 working without examining the special provisions.

22. Common Expenses Requiring Rule 42 Review

In GST audits, the following expenses commonly require Rule 42 review where the registered person has both taxable and exempt activities:

If such expenses are used for both taxable and exempt activities, proportionate reversal should be examined.

23. Rule 43 Requires Capital Goods Register

For Rule 43, the registered person should maintain a capital goods register showing:

Without such a register, it becomes difficult to defend Rule 43 compliance during departmental audit.

Part F - Common Mistakes Found in GST Audit

24. Conclusion

Rule 42 and Rule 43 are core ITC apportionment provisions under GST. Rule 42 deals with inputs and input services, while Rule 43 deals with capital goods. Both rules become relevant whenever inward supplies are used commonly for taxable and exempt supplies, or for business and non-business purposes.

The most important practical point is that reversal is not to be calculated on total ITC . The registered person must first identify exclusive taxable ITC, exclusive exempt ITC, non-business ITC, blocked credit and common credit. Only the common portion is subjected to proportionate reversal.

Every registered person having mixed supplies should maintain invoice-wise ITC classification , turnover reconciliation , Rule 42 monthly and annual working , Rule 43 capital goods register and proper GSTR-3B Table 4(B)(1) reporting. Proper documentation and accurate return reporting are essential to avoid demand, interest and penalty exposure.