Section 80 of the Income-tax Act, 2025 — Fair Market Value Deemed to be Full Value of Consideration (Capital Gains)

In plain language

What Section 80 actually says

Section 80 of the Income-tax Act, 2025 deals with a narrow but important situation in capital gains: what do you do when you sell a capital asset but the consideration (the amount you received) cannot be figured out? The rule is simple — if the consideration received or accruing on transfer of a capital asset is not ascertainable or cannot be determined, then the fair market value (FMV) of that asset on the date of transfer is treated as the "full value of consideration" for computing capital gains.

This is the 2025 Act's re-enactment of the old Section 50D of the Income-tax Act, 1961. The wording and effect are substantially the same; only the section number has changed under the new Act (effective 1 April 2026).

Why this section exists

Capital gains are normally computed as: Full value of consideration − (Cost of acquisition + Cost of improvement + Transfer expenses). The whole formula collapses if the "full value of consideration" is unknown. Before this rule, taxpayers sometimes argued that because no money price could be pinned down, capital gains could not be computed at all — and therefore nothing was taxable. Section 80 closes that gap by supplying a substitute figure: the FMV on the date of transfer.

Who and what it applies to

• Only capital assets. It applies to transfer of a "capital asset" and income taxable under the head Capital gains. It does not apply to stock-in-trade or business income.
• Any taxpayer — individuals, HUFs, firms, companies, LLPs — whenever they transfer a capital asset for a consideration that cannot be quantified.
• Typical triggers: pure barter/exchange of assets where no money is involved, transfer against consideration that is contingent or unquantifiable, or certain complex/illiquid transfers where a price simply cannot be established.

The one key condition — "not ascertainable"

This is the gatekeeper. Section 80 applies only when the consideration genuinely cannot be determined. It does not apply merely because the price is low, inadequate, or the parties are related. If you actually received a price — even a small one — that real price is used, and Section 80 does not step in. The burden is generally on the taxpayer to show why the consideration is not ascertainable.

How fair market value is determined

• FMV is broadly the price the asset would fetch in the open market on the date of transfer.
• Where an open-market price is not readily available, FMV is worked out using the prescribed valuation rules (in the 1961 regime, Rule 11U / 11UA and related rules for shares and other assets). Equivalent rules apply under the 2025 framework.

How it interacts with related deeming sections

Section 80 is one of a family of "deemed consideration" rules — it is important not to confuse them:

• Section 50C (1961) / the 2025 equivalent — for land and building, uses the stamp-duty value if it exceeds the actual sale price. Here a price exists; it is just tested against stamp value.
• Section 50CA (1961) / the 2025 equivalent — for unquoted shares, substitutes FMV if the sale price is lower.
• Section 80 (2025) / 50D (1961) — different in kind: it applies only when no ascertainable consideration exists at all, not when a low price needs to be tested.

Practical implications

• You cannot escape capital gains tax simply by structuring a transfer with an "unquantifiable" price — the FMV plugs the hole.
• Documentation matters. Keep a proper valuation report (from a registered valuer/merchant banker where required) to defend the FMV you adopt.
• Cost of acquisition, indexation (for eligible long-term assets), exemptions and the applicable capital-gains rate all continue to operate normally once FMV replaces the missing consideration.
• Under-reporting the correct FMV can attract heavy penalties, so getting the valuation right is critical.