Procedure · Tax and money

Correcting your French tax return: before the deadline, after the notice, then by claim

A forgotten box, a wrong amount, actual expenses to add: during set periods, you correct your return yourself online, without writing to anyone. Once the correction service has closed, you can still file a claim until 31 December of the second year after your tax was put into collection (the date is on your notice).

At a glance

Who: Any household that filed online or validated its automatic return and spots a mistake; on paper, you use an amended return or a claim.
When: Before the deadline: as often as you like. After the notice: while the correction service is open (in 2026, from 29 July to 30 November inclusive). After that: a claim.
Where: In your online tax account (espace Finances publiques, formerly espace particulier): the online return before the deadline, the “Corriger ma déclaration en ligne” service after the notice, secure messaging after that.
Cost: Free. A good-faith mistake you correct yourself normally carries no surcharge; if extra tax is due, the late-payment interest is halved.
How long: After an online correction, the corrected tax notice usually arrives about 3 weeks after it has been processed.

Online correction service (espace Finances publiques)

Step by step

Before the deadline: reopen your return. Until your département's deadline has passed, you can change your online return as many times as you like, even after signing it. On paper, send a complete new return marked “DÉCLARATION RECTIFICATIVE, ANNULE ET REMPLACE” (amended return, cancels and replaces) on the first page.
After the notice: open “Corriger ma déclaration en ligne”. Once the notices are online, the correction service opens in your online tax account (in 2026, from 29 July to 30 November inclusive): click “Accédez à la correction en ligne” (go to the online correction). It also works if you validated an automatic return; if you filed with the impots.gouv app, you can correct it from the app.
Fix the amounts and boxes. You find the sections of your return again: change an income, add actual expenses, a deduction or a dependant, tick or untick a box. Save the acknowledgement; an email confirms it was sent.
Know what the service cannot correct. A marriage, PACS, divorce or death, your civil status, your address, a student's address or your trusted third party cannot be changed here. For these, write through the secure messaging service: “Écrire” (write), then “Réclamation, contestation” and “Impôt sur le revenu”.
Get your corrected notice and new rate. The tax office may ask for details, or even refuse the correction. Once it is processed, a corrected notice usually arrives within 3 weeks with the new balance, and your withholding rate is recalculated. A correction made after the filing deadline counts as late: the new notice comes later than usual.
Service closed or paper return: file a claim. After the service closes, or if you filed on paper, a correction goes through a claim, possible until 31 December of the second year after the collection date shown on your notice (until 31 December 2028 for tax put into collection in 2026). File it through secure messaging, with your supporting documents.

Documents to prepare

Your tax notice (to spot the mistake and the collection date)
Proof of the right amount: December payslip, statement from France Travail or your pension fund, donation receipt, childcare invoice
The breakdown of your actual expenses if you add them
Your impots.gouv.fr login details

Pitfalls to avoid

The correction service closes on a fixed date (30 November in 2026): after that, you need a claim.
Changes of family situation and address do not go through the online correction, but through secure messaging.
A correction that increases your tax is owed with late-payment interest, halved if you correct it spontaneously and in good faith.
The right to make a mistake (droit à l'erreur) covers neither a late return nor a late payment.

What Nego does for you

Spot the mistake by comparing your notice with your payslips and statements
Recalculate your corrected tax with the site's income tax simulator
Write your secure message request when the online correction is no longer possible
Work out forgotten actual expenses with the actual expenses tool

Nego follows the checked steps on this page, does the calculations with the site's tools and drafts your letters. It does not replace the administration: the procedure is completed on the official service.

Going further

Income tax simulator Actual expenses or flat deduction Withholding tax rate calculator Tax withheld at source Payslip explained

Frequently asked questions

How many times can I change my return?

Before the deadline, as often as you like. After the notice, the online correction service stays open until its closing date; after that, only a claim is possible.

I forgot to claim my actual expenses, is it too late?

No. Add them with “Corriger ma déclaration en ligne” while the service is open, then by claim until 31 December of the second year after the collection date. If you filed on paper, go straight to a claim.

I left out some income: will I be penalised?

If you are acting in good faith and correct it yourself, you pay the extra tax with no surcharge or fine in the vast majority of cases; the late-payment interest is halved. The right to make a mistake does not cover a late return.

Does the correction change my withholding rate?

Yes: once processed, your rate is recalculated and sent to your employer. After a late correction, the new rate only shows in your account once the tax office has processed it.

I entered the wrong family situation, how do I fix it?

Not with the correction service: write through secure messaging (“Écrire”, “Réclamation, contestation”, “Impôt sur le revenu”), attaching proof of your situation.

Official sources

Rules checked on 27 October 2026 against the sources above. This page explains the procedure; it replaces neither the administration nor legal advice.

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Correcting your French tax return: before the deadline, after the notice, then by claim

At a glance

Who

Any household that filed online or validated its automatic return and spots a mistake; on paper, you use an amended return or a claim.

When

Before the deadline: as often as you like. After the notice: while the correction service is open (in 2026, from 29 July to 30 November inclusive). After that: a claim.

Where

In your online tax account (espace Finances publiques, formerly espace particulier): the online return before the deadline, the “Corriger ma déclaration en ligne” service after the notice, secure messaging after that.

Cost

Free. A good-faith mistake you correct yourself normally carries no surcharge; if extra tax is due, the late-payment interest is halved.

How long

After an online correction, the corrected tax notice usually arrives about 3 weeks after it has been processed.

Step by step

Before the deadline: reopen your return. Until your département's deadline has passed, you can change your online return as many times as you like, even after signing it. On paper, send a complete new return marked “DÉCLARATION RECTIFICATIVE, ANNULE ET REMPLACE” (amended return, cancels and replaces) on the first page.

After the notice: open “Corriger ma déclaration en ligne”. Once the notices are online, the correction service opens in your online tax account (in 2026, from 29 July to 30 November inclusive): click “Accédez à la correction en ligne” (go to the online correction). It also works if you validated an automatic return; if you filed with the impots.gouv app, you can correct it from the app.

Fix the amounts and boxes. You find the sections of your return again: change an income, add actual expenses, a deduction or a dependant, tick or untick a box. Save the acknowledgement; an email confirms it was sent.

Know what the service cannot correct. A marriage, PACS, divorce or death, your civil status, your address, a student's address or your trusted third party cannot be changed here. For these, write through the secure messaging service: “Écrire” (write), then “Réclamation, contestation” and “Impôt sur le revenu”.

Get your corrected notice and new rate. The tax office may ask for details, or even refuse the correction. Once it is processed, a corrected notice usually arrives within 3 weeks with the new balance, and your withholding rate is recalculated. A correction made after the filing deadline counts as late: the new notice comes later than usual.

Service closed or paper return: file a claim. After the service closes, or if you filed on paper, a correction goes through a claim, possible until 31 December of the second year after the collection date shown on your notice (until 31 December 2028 for tax put into collection in 2026). File it through secure messaging, with your supporting documents.

Pitfalls to avoid

The correction service closes on a fixed date (30 November in 2026): after that, you need a claim.

Changes of family situation and address do not go through the online correction, but through secure messaging.

A correction that increases your tax is owed with late-payment interest, halved if you correct it spontaneously and in good faith.

The right to make a mistake (droit à l'erreur) covers neither a late return nor a late payment.