Last few days remaining to modify 2025 tax declaration online in France

Tax payers in France still have a few days remaining to make changes online to their 2025 French tax declarations, covering 2024 income.

Although the deadline to file tax returns passed earlier this year, the online correction service remains available until Wednesday, December 3, closing promptly at 23:59.

This allows taxpayers to add or modify any omissions or errors such as:

• income declared from salaries, pensions, property income, etc

• deductible expenses and tax reductions/credits

• professional expenses

How can I modify my French tax return?

Log in to your personal account on impots.gouv.fr, then select: Accédez à la correction en ligne (Access online correction).

You will receive an updated avis (tax statement) once you have made the changes, indicating the new level of the tax you are expected to pay if required. 

However, note that the avis is not processed automatically and may take some time to appear in your account.

If you made your original declaration using the impots.gouv app, be aware you can only make changes via the same interface.

If you declared your income using a paper form, you have up to two years after submission to make corrections. You can do this via the Messagerie sécurisée (Secure messaging service) on your impots.gouv account, or by sending a letter to your local tax office.

What changes cannot be made via the online correction service?

You must contact your local tax office directly in writing or via your impots.gouv account to modify certain details.

These specific details include:

• changes in family status (marriage, civil partnership, divorce, separation)

• changes of address

• the appointment or change of a trusted third party

Is it possible to make changes after December 3?

Online corrections after this date will no longer be possible. 

However, if you do notice an error there are alternative means - you can opt to:

• send a message to your personal tax department via the messaging system on your impots.gouv account

• send a letter to your local tax office explaining the specific reason for your claim, alongside your full name, full address, tax number, handwritten signature, and any supporting documents

• seek assistance at your local Service des impôts des particuliers (SIP) office

How can I update my tax rate for 2026?

If your taux de prélèvement à la source (taxed-at-source rate) changed in 2025, this only stays valid until December 31.

To extend it into 2026, a new application must be submitted via your impots.gouv account before Saturday, December 6. 

Log into your personal account and click on Gérer mon prélèvement à la source section, and then Actualiser suite à une hausse ou une baisse de vos revenus. 

This allows tax authorities to take more recent information into account when estimating your projected income for the coming year, using information from the actual 2025 year instead of your spring 2025 declaration for 2024. 

If you do not know exactly how much you expect to earn in the coming year, you can estimate it by increasing your net income by 3%.