First use creates a specific tax-cost boundary
For FY 2025–26 / AY 2026–27, section 43(1), Explanation 8 of the Income-tax Act, 1961 excludes from an asset’s actual cost interest connected with acquisition that relates to a period after the asset is first put to use. It covers interest paid or payable. An accounting capitalisation entry does not override that exclusion, and the lender’s invoice date does not by itself establish the period to which interest relates.
Read the applicable text: Income-tax Act, 1961: section 43(1), Explanation 8.
Build the asset and loan chronology
Collect acquisition records, borrowing terms, drawdowns, principal repayments, commissioning evidence and the supported first-use date. Match each interest accrual to the relevant asset and period. Do not treat invoice date, delivery, readiness for use and actual first use as necessarily identical. Where the use date is disputed, resolve evidence rather than selecting a convenient financial-year boundary.
Separate the tax comparison from book accounting
Prepare columns for book capitalisation, pre-use acquisition interest, post-use acquisition interest and tax adjustments. Book borrowing-cost rules must be applied under their own framework. The tax rule examined here is the express exclusion of the post-use component. Its operation does not prove that every earlier rupee qualifies for inclusion: other actual-cost, borrowing and deduction requirements remain relevant.
Do not turn an exclusion into an automatic deduction
An amount excluded from actual cost needs its own analysis under the applicable interest-deduction and other tax provisions. Do not both deduct the same amount and leave it embedded in a depreciation base. Conversely, an accounting expense label does not settle its tax treatment. Keep the actual-cost adjustment and any supported current deduction as separate computation steps.
Allocate by supported periods and balances
A monthly illustration can be appropriate where its dates and constant principal support it. Changing principal, daily accrual terms, multiple assets and part-month use require a more precise allocation. Do not spread total project interest across assets using an unsupported revenue ratio or apply one asset’s first-use date to all components automatically.
Close the depreciation bridge
Remove the excluded amount from the relevant actual-cost working and assess consequential depreciation and book-to-tax differences under the applicable rules. Preserve earlier-year corrections separately. These references concern the stated return under the 1961 Act; they do not mechanically replace it with Income-tax Act, 2025 tax-year numbering. All pre-use amounts in the examples are assumed independently eligible; the examples isolate the post-use exclusion.
Six worked illustrations
All facts and amounts are fictional. Calculations illustrate the stated assumptions, not a predetermined legal outcome.
Illustrative example 1: Six complete post-use months
A company has constant acquisition borrowing ₹60 lakh at an assumed 10% annual simple rate throughout FY 2025–26. The asset is first used on 30 September 2025 and interest is allocated by complete months on the assumed terms. Annual interest is ₹6 lakh, with ₹3 lakh relating to October–March excluded from actual cost. If base cost is ₹60 lakh and the other ₹3 lakh is independently eligible, the tax-cost working is ₹63 lakh, not ₹66 lakh.
Illustrative example 2: Interest paid later
A lender bills ₹2.4 lakh after year-end: assume accruals relate ₹0.9 lakh to the eligible pre-use period and ₹1.5 lakh to the post-use period. Exclude ₹1.5 lakh from actual cost. Payment or billing timing does not convert all ₹2.4 lakh into pre-use cost.
Illustrative example 3: Different assets, different dates
Assumed acquisition interest is ₹4 lakh for asset A, comprising pre-use ₹1 lakh and post-use ₹3 lakh, and ₹3 lakh for B, comprising ₹2 lakh and ₹1 lakh respectively. Total interest is ₹7 lakh; excluded post-use interest is ₹4 lakh. The assumed independently eligible pre-use total is ₹3 lakh. One common cut-off could misallocate both assets.
Illustrative example 4: Changing principal
After first use, a loan has assumed ₹40 lakh outstanding for three complete months and ₹20 lakh for the next three, at 12% annual simple interest. Post-use interest is ₹1.2 lakh plus ₹0.6 lakh, totalling ₹1.8 lakh. Using ₹40 lakh for all six months would overstate the relevant amount by ₹0.6 lakh.
Illustrative example 5: Remove the amount only once
A book asset amount is ₹52 lakh, including ₹2 lakh of assumed post-use interest. The tax-cost bridge removes that amount once, giving ₹50 lakh before any other tax adjustments. Reducing it again to ₹48 lakh duplicates the same exclusion. Any deduction claim requires its separate legal analysis.
Illustrative example 6: Reconcile an incomplete split
An acquisition-interest ledger totals ₹5 lakh. Supported allocation identifies ₹1.8 lakh pre-use and ₹2.7 lakh post-use, leaving ₹0.5 lakh unresolved. Do not automatically capitalise the residual or expense it merely to balance the working. Resolve the missing period or asset evidence.
Ten-step verification table
| Step | Action | Evidence |
|---|---|---|
| 1 | Identify the asset | Acquisition and asset-register references. |
| 2 | Establish first use | Commissioning and actual-use evidence. |
| 3 | Map acquisition borrowing | Loan terms and drawdowns. |
| 4 | Reconcile total interest | Accrual and lender records. |
| 5 | Split relevant periods | Balance-sensitive interest schedule. |
| 6 | Identify post-use exclusion | Explanation 8 adjustment. |
| 7 | Review pre-use eligibility separately | Supported tax-cost analysis. |
| 8 | Review any current deduction separately | Applicable conditions and no double claim. |
| 9 | Update depreciation workings | Tax basis and consequential differences. |
| 10 | Close unresolved amounts | Signed book-to-tax bridge. |
Sixteen practitioner FAQs
1. Which provision excludes post-use acquisition interest?
Section 43(1), Explanation 8.
2. Does it address only cash interest paid?
No. It refers to interest paid or payable.
3. Does a lender’s billing date decide the relevant period?
Trace the period to which the interest relates.
4. Is first use necessarily the purchase date?
No. Establish the facts.
5. Does book capitalisation override this exclusion?
No.
6. Is every pre-use interest amount automatically tax cost?
Its independent eligibility still requires analysis.
7. Does exclusion guarantee a current deduction?
No. Check the applicable deduction rules separately.
8. Can the same amount remain in the depreciation base and be deducted again?
Avoid an unsupported double claim.
9. Can one first-use date cover every project asset?
Use asset-specific evidence where dates differ.
10. When is monthly allocation suitable?
When the contractual accrual assumptions and complete periods support it.
11. What if principal changes during the period?
Reflect the changing balances in the calculation.
12. What if a part-month is involved?
Use the supported accrual method and precise dates.
13. Can an unexplained residual simply be capitalised?
Resolve the evidence gap first.
14. Does the article prescribe a depreciation rate?
No. Compute the annual allowance separately.
15. Should a correction be removed twice?
No. Preserve a single traceable adjustment for each amount.
16. Which period is addressed?
FY 2025–26 / AY 2026–27 under the Income-tax Act, 1961.
Official sources
Income-tax Act, 1961: section 43(1), Explanation 8
Income Tax Department: section 43, Explanation 8
Income Tax Department: transition to the Income-tax Act, 2025