France's real-estate wealth tax (IFI) rests on a deceptively simple principle: declaring the market value of your property assets as at 1 January. In practice, this valuation is where most tax reassessments arise, because “market value” is never a single figure but a range that the tax authority and the taxpayer read differently.
What the 2025 guidance confirms
This year's clarifications confirm that valuations must rest on real comparables — recent sales of similar properties in the same area — rather than a flat estimate. The comparison method remains the reference; income-capitalisation and reconstruction-cost approaches are admitted only as a fallback, when the local market offers too few comparison points.
The authority also recalls that certain discounts are perfectly legitimate, provided they are documented: an occupied property, joint ownership, or the illiquidity of an atypical asset. Conversely, a systematic and unjustified discount invites reassessment, with penalties.
The discounts to secure
- Occupancy: a let property is worth less than its vacant value, in a proportion justified by the yield and the lease term.
- Split ownership: the division between bare ownership and usufruct follows the tax scale, but the IFI base deserves a case-by-case analysis.
- Joint ownership and SCI shares: the difficulty of selling a share justifies a discount, supported by market references.
For wealth structured through civil-law companies, attention turns to the valuation of the shares and to deductible liabilities: only borrowings genuinely allocated to the taxable asset reduce the base, within now well-defined limits.
Our reading
The point is not to understate a value artificially — the losing strategy par excellence — but to build a defensible valuation, supported by dated comparables and by discounts justified item by item. A robust valuation file, kept up to date each year, remains the best protection in the event of an audit. That is exactly the work we carry out with our clients subject to the IFI: documenting, prioritising, and never leaving value to chance.