Key Takeaways
  • The 2025 income tax filing campaign opened on 9 April 2026, with deadlines staggered from 21 May to 4 June.
  • The Differential Contribution on High Incomes (CDHR) is renewed: a minimum effective tax rate of 20% for incomes exceeding €250,000 (single) or €500,000 (couple).
  • Two distinct CSG rates now apply to investment income: 10.6% (standard) and 9.2% (rental income).
  • The income tax brackets have been adjusted upward by 0.9%, and the charitable donation tax relief cap rises to €2,000.

France’s 2025 income tax filing season opened on 9 April 2026. Beyond the routine annual exercise, this year’s campaign introduces several significant changes that are particularly relevant for high-net-worth individuals. Between the renewal of the CDHR minimum tax, the restructuring of social contribution rates, and bracket adjustments, the stakes are high: a well-prepared return can mean a difference of tens of thousands of euros for a high-income household.

01

2026 Filing Calendar

The online filing service has been accessible since 9 April on Mon espace Finances publiques (impots.gouv.fr). Deadlines are staggered by department:

2026 Filing Calendar
19 May 2026 Deadline for paper returns.
21 May 2026 Online deadline for departments 01 to 19 and non-residents.
28 May 2026 Online deadline for departments 20 to 54.
4 June 2026 Online deadline for departments 55 to 976, including Alpes-Maritimes (06), Var (83), and Bouches-du-Rhône (13) — covering the entire French Riviera.
02

The CDHR: Minimum Tax on High Earners Renewed

Introduced by the 2025 Finance Act as a temporary measure, the Contribution Différentielle sur les Hauts Revenus (CDHR) has been renewed for 2025 income. Its principle is straightforward yet powerful: it guarantees a minimum effective tax rate of 20% on the highest incomes.

The thresholds are €250,000 in reference taxable income for a single taxpayer and €500,000 for a couple filing jointly. In practice, if your income tax — combined with the exceptional contribution on high incomes and flat-rate withholdings on investment income — results in an effective rate below 20%, you will owe a top-up payment. This measure targets, in particular, taxpayers who optimize their tax position through the PFU (30% flat tax) on substantial capital income.

The most exposed profiles include business owners receiving significant dividends, holders of substantial financial portfolios with realised capital gains, and taxpayers combining moderate employment income with high investment income. It is essential to simulate the CDHR impact before finalising your return.

« If your income tax, combined with the exceptional contribution on high incomes and flat-rate withholdings on investment income, results in an effective rate below 20%, you will owe a supplementary payment. »
Direction Générale des Finances Publiques — Finance Act 2025, renewed for 2026
03

Two CSG Rates: A Structural Change

The 2026 Social Security Financing Act introduces an unprecedented distinction in the CSG (Contribution Sociale Généralisée) rates applicable to investment income. This differentiation has a direct impact on property investors:

Income Type CSG Rate Practical Impact
Capital gains, dividends, interest 10.6% (standard rate) Standard rate applies to financial income
Rental income 9.2% (reduced rate) Saving of €1,400 per €100,000 of rental income

This differentiation, combined with the 30% allowance under the micro-foncier regime (for income below €15,000) or deductions under the actual expenses regime, calls for careful analysis of the rental income taxation strategy. The allocation between rental income and financial investment income is no longer fiscally neutral.

04

Updated Tax Brackets for 2026

The income tax schedule has been adjusted upward by 0.9% to offset the effects of inflation. While this revaluation is modest, it mechanically adjusts all bracket thresholds.

2026 Income Tax Schedule — Marginal Rates by Bracket
2025 income, per tax unit — Adjusted +0.9%
Up to €11,520
0%
€11,520 – €29,373
11%
€29,373 – €83,988
30%
€83,988 – €180,648
41%
Above €180,648
45%
05

Five Optimization Strategies to Activate Before Filing

For high-income taxpayers, the following optimization areas should be reviewed this year, in coordination with your wealth management advisor:

Strategy 1

Simulate the CDHR Impact

Calculate your overall effective tax rate to determine whether the top-up will apply, and evaluate possible trade-offs (progressive scale vs. PFU). In some scenarii, opting for the progressive scale may prove more advantageous — an analysis that must be conducted case by case.

Strategy 2

Optimize the Investment Income Mix

With two distinct CSG rates, the allocation between rental income and financial income has a direct tax impact. Shifting certain income streams can generate meaningful savings without altering the underlying asset allocation.

Strategy 3

Review Tax Credits and Deductions

Home employment, charitable donations, overseas investments, Denormandie scheme: ensure all applicable provisions are properly reported. The charitable donation cap rising to €2,000 is an often-overlooked improvement.

Strategy 4

Furnished Rental Regime Choice

The updated micro-BIC thresholds may change the equation between the simplified and real expense regimes. A comparative simulation of both regimes is essential for owners of furnished rentals on the Côte d’Azur.

Strategy 5

Plan for the Tax Notice Payment

If you owe more than €300, payment will be spread over four monthly instalments from September to December. Factor this into your cash flow planning to avoid surprises in the second half of 2026.

Payment Dates

Key Payment Dates

24/31 July: potential refund of overpayment. 25 September: single debit if balance €300 or less. September–December: four monthly debits if balance exceeds €300.

Key Points to Remember
  • The CDHR minimum tax (20% effective rate above €250,000 / €500,000) is renewed for 2025 income — simulation is essential before finalising.
  • The two-tier CSG structure creates a measurable advantage for rental income over financial investment income.
  • Brackets are indexed by 0.9% — modest but meaningful for taxpayers near threshold boundaries.
  • Furnished rental owners must run a comparative micro-BIC vs. real expense simulation given updated thresholds.
  • For Alpes-Maritimes residents, the filing deadline is 4 June 2026 — but optimization work should begin immediately.

The information contained in this article is provided for informational purposes only and does not constitute personalised investment advice or a recommendation to buy or sell any financial instrument. Past performance is not indicative of future results. All investments carry risk, including the risk of loss of capital. Tax laws are subject to change and depend on individual circumstances. Riviera Wealth Management — CIF registered at ORIAS, member of CNCGP.