Taxation and déclarations: VAT, IS, advance payments

Updated April 2026 - Many tax errors come not from bad calculation, but from bad timing. VAT, IS deposit, IS balance, tax package, CA12 or specific obligations: each flow has its own logic. In 2026, good management consists of organizing these deadlines in a single system.

In brief: VAT, IS and advance payment déclarations form the foundation of your 2026 tax obligations. Value added tax is declared via CA3 (standard real régime) or CA12 (simplified régime), with monthly or annual deadlines depending on your turnover. Corporate income tax is levied at 25% (15% on the first €42,500 of profit for SMEs), with four annual advance payments and a balance. Missing deadlines exposes you to 5% to 10% surcharges and late interest.

Value added tax in France operates on four rates, unchanged by the 2026 finance law:

The extended rate for forestry and forest fire prevention works was renewed by Article 96 of Finance Law No. 2026-103 of 19 February 2026 (BOFiP - VAT).

Depending on your tax régime, the déclaration rhythm differs significantly:

Standard real régime#

Companies exceeding simplified régime thresholds file a monthly CA3 déclaration. Electronic payment occurs between the 15th and 26th of the following month, depending on the date assigned in your professional space on impôts.gouv.fr.

Simplified taxation régime (RSI)#

Éligible SMEs submit an annual CA12 déclaration accompanied by a semi-annual advance payment. CA12 E applies to companies exempt from VAT under the franchise en base threshold.

Points of vigilance#

• VAT collected must be reconciled with declared turnover;
• Déductible VAT requires compliant invoices (mandatory mentions, date, intra-community VAT number);
• Rate errors are a classic reason for adjustment during a tax audit.

For more detail, see our guide on the VAT déclaration and our article on VAT reverse charge.

Corporate income tax (IS) is paid in instalments throughout the financial year. The 2026 IS advance payment calendar for companies closing on 31 December provides four deadlines:

The March 2026 first advance was the subject of official communication from the DGFiP and Service Public Entreprendre (Service Public - IS advance March 2026).

What amount for each advance payment?#

Each advance payment corresponds to 25% of the IS amount due for the last closed financial year. If your profit is decreasing, you can reduce your advance payments without penalty, provided you justify the decrease when filing your results déclaration.

Hayot Expertise Advice: A SASU generating €200,000 of taxable profit owes €50,000 in IS (25%). Each quarterly advance is therefore €12,500. Forgetting a single advance triggers an automatic 5% surcharge, or €625 in avoidable penalties.

The standard IS rate is set at 25% since 2022, with no change in the 2026 finance law. SMEs benefit from a reduced rate:

• 15% on the profit fraction below €42,500 (for companies with turnover under €10 million and at least 75% of capital held by individuals);
• 25% on the fraction exceeding this threshold.

The 3.3% social contribution (CSA) on IS applies when the tax amount exceeds €763,000.

The classic trap of VAT, IS and advance payment déclarations is lumping everything under the corporate tax label. In reality, three distinct obligations must be distinguished:

• IS advance payments (4 annual instalments);
• the IS balance (single payment after year-end closing);
• the results déclaration no. 2065 and its annexes (tax package).

For companies closing on 31 December 2025 or 31 January 2026, the electronic payment deadline for the IS balance is set at 15 May 2026. The tax return follows a separate calendar.

The case of 31 December 2025 closings#

For financial years ending on this date, the practical filing date for the tax package via teleprocedure is generally 20 May 2026, taking into account the additional 15-day period granted to EDI-TDFC teleprocedure users.

You can complete with our article on the tax package filing deadline 2026.

We recommend a three-layer management approach to structure your 2026 tax obligations:

1. Monthly recurring obligations#

• CA3 déclaration and VAT payment;
• social déclarations (DSN);
• invoice tracking and déductible VAT monitoring.

2. Closing obligations#

• tax return preparation (2065, 2033, 2050 to 2059);
• IS balance calculation and any supplementary advances;
• results déclaration and tax annexes.

3. Exceptional or sectoral obligations#

• payroll tax, CVAE, property tax;
• intra-community déclarations (DES, DEB);
• sector-specific obligations.

Hayot Expertise Advice: A good tax calendar does not just list dates. It links each deadline to the documents to be produced, the internal manager and the expected level of control. This is the difference between imposed taxation and managed taxation.

We build with our clients an operational tax calendar linking VAT, IS and advance payment déclarations, tax returns and control points. Our service covers deadline review, déclaration preparation and payment security before each due date.

Putting your tax calendar under control

Tax compliance 2026 is as much about the method as it is about the rules. VAT, IS and advance payment déclarations form an interdependent system: a delay in one impacts the others. When deadlines are clearly mapped, taxation once again becomes a subject that is managed, not imposed. An informed business owner is worth two.

(Official sources: impôts.gouv.fr - Professional tax calendar 2026, impôts.gouv.fr - VAT déclaration and payment, impôts.gouv.fr - IS telepayment, BOFiP - VAT rates, Service Public Entreprendre - IS advance March 2026, Finance Law No. 2026-103 of 19 February 2026)