TL;DR: You can deduct the mandatory contributions provided for by Article 154 bis of the CGI, as well as certain supplementary, optional or group insurance contributions, within the applicable limits and conditions. The deduction period depends on the nature of the contribution, its payment and the accounting period to which it relates.
Who can apply the deduction
Article 154 bis of the CGI concerns self-employed workers whose profits are subject to income tax in the category of industrial and commercial profits or non-commercial profits, and who pay contributions to schemes for non-salaried workers.
Which contributions can you deduct?
You can deduct contributions paid to mandatory family allowance, old-age insurance, disability-death, sickness and maternity schemes.
Article 154 bis also provides, subject to conditions, for the deduction of certain mandatory supplementary contributions, group insurance contracts, optional schemes and payments into retirement savings plans.
Mandatory supplementary contributions exceeding the minimum mandatory contribution, as well as optional contributions and premiums, are subject to separate caps. These caps vary according to the coverage financed and the taxable profit; some are calculated based on the annual social security ceiling.
Which accounting period should the deduction be allocated to?
As a rule, you must allocate an expense to the accounting period to which it relates. It must be definitively incurred and constitute a certain liability in principle and amount.
Social security contributions are calculated provisionally each year and then adjusted when your final professional income is known. An adjustment that is certain in principle and can be determined with sufficient accuracy at the closing date may be recorded as a provision in the accounting period to which it relates, even if it becomes payable at a later date.
For a group insurance contract that does not cover risks falling under life insurance, a contribution due may be deducted as an accrued expense when it constitutes a certain liability in principle and amount, subject to the applicable limits and conditions.
For a group insurance contract covering exclusively risks falling under life insurance, in particular a supplementary pension, the deduction is made for the accounting period in which the payment is actually made. It is separate from the tax reduction provided for by Article 199 septies of the CGI.
How to file the declaration
For 2025 income, if you carry out a craft, commercial or liberal profession, you file a single declaration on impots.gouv.fr for the calculation of your personal social security contributions and contributions and your income tax. The usual tax declaration includes a “social” section. If the “Self-employed income declaration” section is not selected automatically, you can select it.
The unified social and tax declaration applies to self-employed workers carrying out a craft, industrial, commercial, agricultural or liberal activity, as well as to doctors and medical auxiliaries under agreement who fall under the relevant scheme. It must be filed electronically, whether or not you are taxable.
Micro-entrepreneurs are not covered by this unified declaration. They continue to file their specific declaration with Urssaf or Cgss for their turnover or revenue.
The income declared on impots.gouv.fr is automatically transmitted to Urssaf or Cgss. This transmission makes it possible to readjust the schedules for provisional contributions and to regularise the final contribution.
CSG and CRDS
CSG and CRDS are calculated on the activity income taken into account for income tax, increased by mandatory social security contributions, excluding CSG and CRDS.
Urssaf sends you a certificate of payment of CSG-CRDS indicating, in particular, the deductible amount of CSG. When the applicable CSG rate is 6.80% on replacement income, the CSG paid is deductible from taxable income. This rule does not allow all CSG or CRDS to be deducted automatically.