Production tax reform: the 2026 assessment and the urgent need to audit your property bases
The landscape of local taxation for manufacturers in France experienced a legislative earthquake with the Finance Act for 2021. The promise was clear: a shock to competitiveness for French industry via a production tax reform on a grand scale. Five years later, at the start of 2026, the initial enthusiasm has given way to heightened vigilance on the part of finance and tax directors.
Technical analysis by Aymeric Givord, local tax manager, shows that theoretical gains are now being eroded by inflationary conditions and increasing local tax pressure.
A 50 % reduction in property tax bases with limited impact over time
The reform introduced by Article 29 of the Finance Act for 2021 introduced a 50 % reduction in the property tax and business property tax (cotisation foncière des entreprises - CFE) tax bases applicable to industrial establishments.
While this reduction has been implemented from 2021, its real impact in 2026 tends to be significantly attenuated by the concomitant changes in local tax parameters, in particular the revaluation of tax bases and the adjustment of rates voted by local authorities.
HICP: the invisible multiplier
Since 2018, the rental values for business and industrial premises are no longer fixed. They are indexed to the Harmonized Index of Consumer Prices (HICP) for November of the previous year.
This automatic revaluation mechanism has major consequences:
- A cumulative mechanical increase : between 2021 and 2025, tax bases increased by 17,25 %.
- Erosion of the tax gain: taking this inflation into account, the announced reduction of 50 % is, in reality, only 41 % for the majority of operators.
- A lasting trend: Without a review of indexation methods, this inflationary trend will continue to weigh on the tax burden of industrial sites for years to come.
Rising local authority tax rates: a further aggravating factor
The second driver of this dynamic is tax rates. Faced with falling revenues and rising operating costs, many local authorities (communes and intercommunalités) have voted to significantly increase their tax rates.
In some areas, the combined effect of rental value increases and soaring tax rates has practically reached annihilate the effects of the reform. For manufacturers, the final bill could turn out to be just as heavy, if not heavier, than before 2021.
Why is auditing your industrial bases a priority in 2026?
In January 2026, a wait-and-see attitude is no longer an option. The local tax system applicable to industrial sites is based on a particularly complex method of calculation: the rental value is determined on the basis of the cost price of land, buildings and fixtures and fittings, in accordance with article 1499 of the CGI.
This mechanism, which is technical and declarative in nature, is one of the most important main sources of tax base errors.
In a context marked by annual base adjustments, thechanges in local authority tax rates and the gradual increase in local taxation, an unidentified anomaly can result in a significant and recurring overpayments in property tax and CFE.
A targeted audit of industrial bases allows you to :
- Secure the rental value used by the authorities,
- Identify any errors in the qualification or scope of fixed assets,
- If applicable, file a claim with the tax authorities within the legal timeframe.
At a time when nearly 40 % of tax claims concern direct local taxes, the verification of tax bases is therefore an important an essential safety lever, This is particularly strategic for manufacturers, for whom these taxes often represent significant, recurring amounts. In 2026, the audit of industrial bases is no longer an exercise in comfort, but one that must be carried out on a daily basis. a lever for securing and sustainably controlling local taxation.
Securing fiscal 2026 and managing future impacts
The opening of the new financial year is the ideal time to engage a local tax audit. This approach makes it possible to :
- Identify reporting anomalies : verify the correct classification of the fixed assets making up the industrial rental value, in order to identify any overvaluation of the tax base.
- Anticipate and partially offset future increases: correction of the tax base recalculates property tax and CFE on the basis of an adjusted rental value. It thus constitutes a compensating lever in the face of annual increases in tax bases, notably indexed to the HICP, and changes in tax rates voted by local authorities.
Recovering overpayments: prescription management
Tax law offers a window of opportunity to correct the past. January 1, 2026:
- The year 2025 is still «open»: you have until December 31, 2026 to file a contentious claim relating to your property tax for the previous year.
- The year 2024 is prescribed: except in very specific cases, errors committed in the 2024 tax year cannot be reimbursed after December 31, 2025. To find out more: we decipher the subtleties of the taxpayer's claim deadlines in our dedicated podcast.
- However, the issue is not limited to past years: correcting the tax base also makes it possible to secure future years, by avoiding the renewal of an erroneous base and limiting the impact of annual revaluations and rate changes on future years.
G.A.C. Group's expertise: securing your local tax system over the long term
With the effects of production tax reform waning, support from experts in local industrial taxation is becoming a lever for profitability.
Our audit is not limited to an accounting verification: it is based on a thorough legal and technical analysis of industrial bases, based on the opposable administrative doctrine and continuous monitoring of case law, to secure the rental value used by the authorities.
Frequently Asked Questions
What is the real impact of inflation on the reform?
Between 2021 and 2025, indexation to the HICP has resulted in a mechanical base increase of 17.25 %. This reduces the promised reduction of 50 % to just 41 % in reality.
Why is my property tax increasing despite the 2021 Finance Act?
The combination of the legal revaluation of tax bases and the increase in rates voted by local authorities can greatly reduce, or even neutralize, the gains expected from the reform.
Is it too late to do something about my past taxes?
No, as of January 1, 2026, you have until December 31 to contest your tax bases for 2025. On the other hand, 2024 is now statute-barred in most cases, except in very specific cases. To keep on top of these deadlines and make sure you don't miss any more repayment opportunities, listen to our podcast: « Time limits for taxpayer complaints" .
Who can benefit from a local tax audit?
A local tax audit can be carried out for any company, whether owner-operator or owner-occupier. However, the stakes are particularly high for industrial establishments, whose rental value is determined according to the accounting method.
Based on the cost price of fixed assets, this complex calculation method frequently generates errors of qualification, scope or application of rules derived from administrative doctrine and case law, with significant and recurring financial impacts.
Local taxation of industrial sites: a challenge to be met
Errors in the tax base can lead to overpaid amounts, which can be reclaimed within the legal timeframe.
