Reform of the social security contribution base for the self-employed in 2026: single base and 26% allowance.

Since April 2026, social security contributions and the CSG-CRDS (General Social Contribution and Contribution to the Repayment of the Social Debt) for self-employed workers have been calculated on a single basis. A flat-rate allowance of 26%, automatically applied by the Urssaf (French social security agency), replaces the actual deduction of contributions and deductible CSG. The reform applies to final contributions for 2025 and those for 2026 and subsequent years. It reduces the CSG-CRDS portion and increases the portion of contributory contributions. According to service-public.fr, the contribution rates and some other contribution brackets will also change in 2026.

This page describes the mechanism according to service-public.fr and impots.gouv.fr. It does not cover: the case of micro-entrepreneurs, the effect of the euro reform on a given case, the new contribution rates, the details of the boxes on form 2042-C-PRO, or the content of the regulatory texts. For these points, the rule depends on your situation and should be verified before making a decision.

What the reform changes

According to impots.gouv.fr, the tax base "is no longer calculated based on net taxable income." The online tax return process has been modified.

The timetable

• April 2026 : the reform is applicable from the opening date of the 2025 income tax return campaign, according to the news page of service-public.fr of 20/04/2026.
• Final contributions for 2025 : they are calculated from actual 2025 incomes and are part of the reform.
• Contributions for 2026 and subsequent years : them too.
• Reference income : the service-public.fr fact sheet on social protection for craftsmen and traders, checked on 08/10/2026, indicates that contributions paid in 2026 are calculated on the professional income of the year 2025, declared in April-June 2026.

The administration specifies that the reform is applicable from 2025 income and that it was voted in the social security financing law for 2024.

How is income determined?

For a sole proprietorship, the service-public.fr website provides two options:

The Urssaf then applies the standard allowance of 26 %. The information sheet specifies that this allowance "is similar to social security contributions and the deductible CSG (General Social Contribution)." According to impots.gouv.fr, it replaces the actual deduction of these elements. For self-employed professionals, the corresponding information sheet indicates that the 2025 income is taken before the 26 % allowance applied by the Urssaf.

Who is affected?

According to impots.gouv.fr, the reform concerns the basis for social security contributions for self-employed workers, contracted medical practitioners and allied health professionals, as well as the agricultural population. The DGFiP leaflet (reference Urssaf NAT6913, March 2026) is presented "for self-employed workers, medical practitioners or allied health professionals" and does not mention micro-entrepreneurs. The news page on service-public.fr displays a banner: "The page you are viewing does not concern micro-entrepreneurs." Therefore, this page does not address their situation.

Why more contributions and less CSG-CRDS?

According to service-public.fr, the share of the CSG-CRDS (General Social Contribution and Social Debt Repayment Contribution) decreases while the share of social security contributions increases. According to impots.gouv.fr, the reduction in the CSG-CRDS tax base allows for a decrease in the non-contributory portion allocated to the CSG-CRDS. The website also indicates that the reform gives more weight to contributory contributions, "which allow individuals to acquire rights." The leaflet outlines two objectives: to simplify the calculation basis and to improve social rights, particularly pensions.

For the CSG-CRDS on professional income, the factsheet shows an overall rate of 9.70 per % in 2026 (CSG 9.2 per % and CRDS 0.5 per %). The contribution rates for each risk are listed on this factsheet; this page does not reproduce them.

What the sources say about the overall cost

The DGFiP leaflet states: "The total amount of your social security contributions remains the same as before the reform."«

The fact sheets on service-public.fr also indicate that, in 2026, the social base (calculation basis) as well as the scales of social contributions and levies will change (news of 20/04/2026), and that some contribution rates will change (fact sheet on social protection for craftsmen and traders).

The leaflet's statement concerns the reform of the contribution base and does not exempt you from verifying your own contributions. In your case, the amount to be withheld should be verified with the Urssaf (French social security agency) and the official sources cited at the end of the page. This page does not indicate a decrease or an increase.

The texts cited

• The news page of service-public.fr cites decree no. 2024-688 of July 5, 2024, setting out the methods for calculating social security contributions.
• The fact sheet on social protection for craftsmen and traders cites decree no. 2025-708 of July 25, 2025, relating to the basis of the generalized social contribution and social contributions due by self-employed workers.

These two pages do not cite each other. This page does not compare the two texts and does not detail their content.

Numerical example (fictitious profile)

Situation. Nadia is a self-employed craftswoman, subject to income tax. In 2025, her turnover is €150,000 and her operating expenses are €90,000. These expenses do not include social security contributions or deductible CSG (assumptions of the hypothetical profile).

Issue. What basis does the Urssaf use for contributions paid in 2026, calculated on 2025 income, after the allowance?

Strategy. Calculate the income (turnover less expenses), then apply the standard allowance of 26 %.

Result.

This calculation stops at the basic level. It does not calculate any contributions: the way the allowance is factored into the calculation of each contribution is not addressed here. Nadia is a fictional profile. The figures illustrate the arithmetic of the allowance, not a real-life situation.

What changes depending on your situation

• Your status : craftsman, trader, liberal profession, contracted medical practitioner or auxiliary, agricultural activity. The case of micro-entrepreneurs is not addressed here.
• Your method of taxation : income tax or corporation tax, which changes the way income is determined.
• Your salary : operating expenses or actual professional costs.
• Your cash register Some liberal professions fall under funds whose contribution rules differ.
• Your social rights The reform increases the contributory portion of contributions. What this means for your pension can be seen on your pension statement.

No results are promised.