Cost Inflation Index
Also written CII · Cost Inflation Index (CII) · Indexation
An index notified by the CBDT each year, with 2001-02 as the base of 100, used to restate the cost of a long-term capital asset in current rupees so that inflation is not taxed as capital gain.
In plain language
A flat bought for Rs 50 lakh in 2002 and sold for Rs 3.5 crore today has not made Rs 3 crore of real profit. A large part of the rise is simply that rupees are worth less than they were.
Indexation is the Income Tax Act's way of removing that part before taxing what remains. The Cost Inflation Index is the number series that does it: the CBDT notifies a figure for each financial year, with 2001-02 set at 100, and the original cost is scaled up by the ratio of the two years' indices.
What is left after indexation is the gain in real terms — and only that is taxed.
How it works
The Finance Act, 2024 changed when indexation is available, and this is now the most examinable part of the topic.
Transfers before 23 July 2024 — indexation is available on all asset classes, barring certain exceptions.
Transfers on or after 23 July 2024 — indexation is not available, except for land or building or both acquired before 23 July 2024.
For that surviving exception the workbook sets out a parallel test. If immovable property was acquired before 23 July 2024 but transferred after it, compute the tax both ways — at 20% with indexation, and at 12.5% without — and the lower tax applies. One restriction rides with it: any loss created by indexation is no longer allowed.
Where the property was acquired after 23 July 2024, there is no choice at all: 12.5% on the unindexed gain.
A second rule sits underneath the formula: the denominator is the CII of the year the asset was first held by the assessee, or of 2001-02, whichever is later. An asset bought in 1994 is indexed from 2001-02, not from 1994.
The formula
CII of the year of transfer
Indexed cost = Cost x ---------------------------------------
of acquisition CII of the year the asset was first held
by the assessee, or CII of 2001-02,
whichever is LATER
Selected notified values: 2001-02 = 100, 2002-03 = 105, 2011-12 = 184, 2014-15 = 240, 2020-21 = 301, 2023-24 = 348, 2024-25 = 363.
A worked example
The workbook's own case. A Mumbai house cost Rs 50,00,000 in FY 2002-03 (CII 105) and is transferred in FY 2020-21 (CII 301):
Indexed cost = 50,00,000 x 301 / 105 = Rs 1,43,33,333
The cost has nearly trebled on paper without a rupee being spent — and Rs 93 lakh of apparent gain has just disappeared from the tax base.
The post-23-July-2024 parallel test. A flat bought in FY 2011-12 for Rs 40,00,000 (CII 184) is sold on 1 December 2024 — FY 2024-25, CII 363 — for Rs 1,60,00,000. It was acquired before 23 July 2024 but transferred after, so both routes must be computed.
| With indexation | Without indexation | |
|---|---|---|
| Cost taken | 40,00,000 x 363/184 = Rs 78,91,304 | Rs 40,00,000 |
| Capital gain | Rs 81,08,696 | Rs 1,20,00,000 |
| Rate | 20% | 12.5% |
| Tax | Rs 16,21,739 | Rs 15,00,000 |
The lower tax is Rs 15,00,000, so the unindexed route applies — even though indexation removed Rs 39 lakh of gain. The lower rate beat the larger deduction. That inversion is exactly what the examiner is testing: the taxpayer does not choose the method, the arithmetic does.
Why NISM asks about it
Chapter 8 (Capital Gains), section 8.5 covers the indexed cost of acquisition, the CII formula and the 23 July 2024 cut-off, and Annexure 3 prints the full notified table. Chapter 10 and Chapter 12 then apply the no-indexation rule to debt products, gold and property. Expect a computation: you will be given a purchase year, a sale year and two index values, and asked for the indexed cost or the tax — and increasingly, asked to run the parallel calculation and say which answer stands.
Common exam traps
- The base year is 2001-02, not the year of purchase. An asset acquired in 1996 uses the CII of 2001-02 in the denominator, so pre-2001 inflation is never indexed.
- Indexation is largely gone for transfers on or after 23 July 2024 — the only survivor is land or building acquired before that date. Applying the old rule to a mutual fund or a bond is a marks-losing habit.
- The parallel calculation compares tax, not gain. A smaller gain at a higher rate can still be the worse answer, as above.
- A loss produced by indexation is not allowed. Indexation can reduce the gain to nil; it cannot manufacture a deductible loss.
- Cost of improvement is indexed separately, from the year the improvement was incurred, and only capital expenditure on or after 1 April 2001 counts at all.
- CII is not household inflation. It is a notified tax figure. Do not use it as an inflation assumption in a retirement plan, or a general inflation forecast in a capital gains computation.
Check yourself
1.In the indexed cost of acquisition formula, what is used as the denominator?
- a)The CII of the year in which the asset is transferred
- b)The CII of the year in which the asset is first held by the assessee, or the CII of 2001-02, whichever is later
- c)The CII of 2001-02 in every case
- d)The CII of the year in which the assessee filed his first return
Show the answer
Answer: (b) The CII of the year in which the asset is first held by the assessee, or the CII of 2001-02, whichever is later
The formula is Cost of Acquisition × CII of the year in which the asset is transferred ÷ CII of the year in which the asset is first held by the assessee OR CII of 2001-02, WHICHEVER IS LATER. The "whichever is later" matters because 2001-02 is the base year — for an asset first held in 1985 you cannot go behind 2001-02. For the indexed cost of improvement, the denominator is the CII of the year the improvement was made.
Where this is taught
Free preparation for NISM Series X-BRelated terms
- InflationA sustained general rise in the price level, which erodes what a rupee buys — and the reason a nominal return has to be deflated before it means anything.
- Capital Gains Account SchemeA deposit scheme letting a taxpayer claim a capital gains exemption (Sections 54, 54B, 54D, 54F, 54G) even if reinvestment is not done before the tax return is due, by parking the unused gain in a designated account.
- Indexed cost of acquisitionCost of acquisition scaled up by the Cost Inflation Index, so that only the real gain is taxed; withdrawn for transfers on or after 23 July 2024 except for land or building acquired before that date.
- Long-term capital assetA capital asset held for more than the prescribed period before transfer — generally more than 24 months, and more than 12 months for listed securities and equity oriented fund units.
- Cost of improvementCapital expenditure incurred on or after 1 April 2001 on additions or alterations to a capital asset, by the owner or a previous owner, deducted along with cost of acquisition in computing capital gains.
- Assessment year (Section 2(9))The 12-month period beginning 1 April, defined by Section 2(9), in which income earned in the preceding previous year is assessed and taxed — for FY 2021-22, the assessment year is 2022-23.
- Cost of acquisitionWhat an assessee is treated as having paid for a capital asset — usually the price actually paid, but overridden by special rules for bonus shares, ESOPs, gifts and inherited assets.
- Parallel calculationFor land or buildings bought before 23 July 2024 but sold after, the requirement to compute tax two ways, 20% with indexation and 12.5% without, and pay whichever is lower.