CDHR: when French cross-border workers pay the 95% advance payment

Context

TL;DR

• The CDHR aims for minimum taxation of 20%
• The reference taxable income determines the scope
• The indicated thresholds are 250.000 and 500.000 euros
• The advance payment provided for was 95% by December 15, 2025

Key facts

• Measure → differential contribution on high incomes (CDHR)
• Tax residence → France in 2025
• Threshold for a couple → 500.000 €
• Payment → personal space on impots.gouv.fr

Published in February 2026, the guide on the differential contribution on high incomes describes a new French tax measure that may cause a new item to appear on the tax certificate of those who live in France and receive a Swiss salary or mixed income from France and Switzerland. The CDHR aims to ensure minimum taxation of 20% for certain households with high incomes.

The three cumulative requirements

The measure does not automatically concern all high incomes. The source indicates three conditions that must occur together. The first is tax residence in France in 2025: anyone who declares their income in France falls within the scope described by the guide.

The second concerns the adjusted reference tax income for CDHR purposes. The thresholds are assessed at household level: the text indicates 250.000 euro and 500.000 euro, with 500.000 euro for a couple filing jointly.

The third condition is the actual level of taxation. If income tax, added to the exceptional contribution on high incomes (CEHR), does not reach 20% of the income considered, the CDHR covers the difference. If instead the calculation reaches at least 20%, the contribution remains at zero, even with very high incomes.

The calculation does not look only at how much was paid in France. It starts from the reference tax income and an average tax rate. For this reason, a Swiss salary may remain included in the base used for the CDHR even when the French-Swiss tax treaty avoids double taxation through a tax credit.

This point applies to cross-border workers resident in France, including those who receive a Swiss salary and manage their tax position across the border. The guide specifies, however, that in most cases, a profile based solely on a Swiss salary produces a CDHR equal to zero. Numerical verification remains necessary when the overall level of income, financial income, exceptional income or family situation changes. To organize the initial data, calcolatore stipendio can be used, without confusing an estimate with the actual payment.

Operational details

Three profiles, three outcomes

The most practical way to understand the effect of the CDHR is to distinguish between exceeding the thresholds and the outcome of the final calculation. The source presents three profiles, with different consequences also for those who live in France and receive Swiss income:

| Profile | Situation | Consequence | | A | Income below the thresholds | The guide advises leaving the page | | B | Thresholds exceeded, CDHR simulation at zero | No advance payment is submitted | | C | Thresholds exceeded, positive CDHR | The amount is estimated and the advance payment is paid |

Profile A does not fall within the field described. In profile B, income is high enough to exceed the threshold, but the minimum taxation calculation does not generate an amount to be paid. Only profile C leads to the advance-payment stage. This distinction avoids treating simply exceeding the limit as automatic proof of a liability.

The specific point for those receiving a Swiss salary

Withholding tax in Switzerland does not by itself conclude the review. The guide explains that Swiss income remains included in the reference taxable income used for the CDHR, even when the French-Swiss tax treaty avoids double taxation by means of a tax credit. The check, therefore, does not merely compare the tax paid in France with the salary: it considers a broad base and an average rate calculated according to the rules of the mechanism.

The practical consequence is twofold. On the one hand, most profiles based solely on a Swiss salary result in a CDHR equal to zero. On the other hand, it is not enough to stop at this general rule: financial income, exceptional income, the overall level of income and family situation may shift the outcome of the simulation. The guide does not indicate a single figure valid for everyone, precisely because the result depends on the combination of the household's factors.

For cross-border workers, the correct question is not only how much was withheld in Switzerland, but what result emerges after the French calculation. dichiarazione delle imposte should therefore be read together with the data on 2025 income and the CDHR simulation, always distinguishing between a result equal to zero and a positive contribution. The new item may appear on the tax certificate when the calculation leads to an amount due; simply having Swiss income is not enough, on its own, to determine the advance payment.

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Key points

Procedure and deadlines

The operational part required two distinct steps: first estimate the CDHR, then pay the advance. The source warns that the simulation does not collect any amount and that the declaration had to include both what had already been received and a forecast for the end of the year.

The four steps

1. Reconstruct the 2025 income. For the advance, it was necessary to consider the income earned as of December 1, 2025, and estimate that received between December 1 and December 31, 2025. The December estimate was not optional in the calculation indicated by the guide: it was needed to determine the amount relating to the whole of 2025.

2. Estimate the CDHR. The simulator was used to check whether the person fell within the scope of the scheme and to calculate the estimated amount. However, it was not the payment tool. The result to check was the CDHR due, not merely whether the threshold had been exceeded.

3. Determine the advance. When the CDHR was positive, the advance corresponded to 95% of the estimated amount for 2025. The scheduled window was from December 1 to 15, 2025, and by February 2026 it had already passed. For those reading after that deadline, the guide indicated contacting the relevant services if the deadline had been missed.

4. Validate the payment. The operation was carried out in the personal area of impots.gouv.fr, through the «Prélèvement à la source» service, with a bank debit at the time of validation. Once the declaration and payment had been validated, it was not possible to submit an amended declaration. If the estimate had been too low, an additional payment was possible through December 24, 2025, inclusive.

The source also indicated two subsequent outcomes. A 20% surcharge could apply in the event of late or non-payment, or when the advance paid was insufficient, with a difference of more than 20% compared with 95% of the CDHR ultimately due. If, on the other hand, more than necessary had been paid, the excess had to be refunded.

To keep income collection, simulation and payment separate, it is advisable to note the three stages and not consider the simulator’s result as a receipt. After checking the data, use calcolatore stipendio to organize the estimate.

Source: guidedufrontalier.com