October 1, 2026

CIR tax control: how does the control work and what does the administration check?

A fiscal control by the CIR can focus on both the eligibility of the research operations declared and the actual expenditure included in the Research Tax Credit.

The administration can thus examine the nature of R&D work, personnel expenses, time spent on operations, the qualifications of employees, and the consistency between the technical dossier, HR data, accounting elements, and the available supporting documents.

Two situations in particular must be distinguished: the spot check, carried out remotely, and the Accountancy verification, This is part of a more thorough fiscal control of the company. The procedures and guarantees for the taxpayer vary depending on the type of control.

The challenge is therefore to be able to explain the choices made during the declaration and, above all, to have the elements to justify them several months or several years after the work has been carried out.

Why anticipate the CIR tax control more?

The general context of fiscal control is evolving with the increased use of data by the administration. In 2025, the DGFiP has notified 17.1 billion euros in fines and penalties as a result of tax audits. This amount covers all forms of taxation and not specifically the CIR. In the same year, 52 % of the cases involving professionals closed by the DGFiP’s services were referred thanks to artificial intelligence and data mining technologies (economie.gouv.fr).

For companies declaring the CIR, this development particularly reinforces the importance of the consistency of the declared information and its traceability.

The experience of our experts also shows that increase in requests regarding the reality of the teams’ involvement, the Justification of the times and the available evidence at the time the work was being carried out.

This does not mean that there is a public list of criteria that automatically lead to control. The modalities for the programming of fiscal control are evolving and remain largely dependent on the analysis carried out by the administration.

To be read soon: What elements can trigger a CIR tax inspection?

Control over parts or accounting verification: what difference?

These two procedures can lead to the CIR being reviewed, but they do not exactly follow the same rules.

Control over parts

Accountancy verification

Modalities

Remote control

In-depth review of the company’s tax situation

Exchange

Requests for information and supporting documents

Oral and adversarial debate with the auditor

CIR

Can intervene, in particular, following a request for reimbursement or a corrective statement (main causes, but not exhaustive).

It can integrate the examination of the CIR into a more comprehensive control.

Scientific expertise

Possible depending on the circumstances

The administration may request expertise regarding the scientific eligibility of the operations

Procedural guarantees

More limited

Specific guarantees provided as part of the verification

The control of documents is carried out from the administrative offices. In the context of the CIR, it can, among other things, be the result of a request for the reimbursement of a debt or a rectification declaration.

Accountancy verification, on the other hand, provides the guarantees provided for in the Charter of the rights and obligations of the audited taxpayer, whose provisions are binding on the administration.

To be read soon: Control of CIR items: how does the procedure work?

What does the administration check during a CIR tax inspection?

Requests vary depending on the companies and the operations declared. However, several topics regularly come up in the audits conducted by our experts.

The scientific eligibility of R&D operations

A complex, innovative or technically ambitious project is not necessarily an R&D operation eligible for the CIR. The company must be able to characterize their work in terms of the criteria specific to research and experimental development.

The Guide to the Research Tax Credit The Ministry responsible for Research refers in particular to the five criteria set out in the Frascati Manual: novelty, creativity, uncertainty, systematization and transferability or reproducibility.

Our expert reports also show that the analysis can be performed operation by operation and exercise by exercise. A project that is recognized as eligible one year should therefore not be considered automatically eligible for its entire duration.

The border between R&D and conventional development It is particularly important to note that the CIR Guide itself reminds us that experimental development and product development should not be confused.

To be read soon: CIR scientific expertise: what criteria does the expert examine?

The real involvement of the staff in the work

The verification of personnel expenses does not necessarily stop at the employee’s salary, degree, or CV. The observed requests can also relate to their specific role in the R&D operation, his job description, his employment contract and the elements that demonstrate concretely his involvement.

Agendas, emails, technical notes, reports or deliverables can thus be part of the set of elements that make up the employee’s involvement during the work. The goal is to be able to link them coherently. the collaborator, the work he has carried out and the R&D operation in which his expenses are valued.

The consistency of the time devoted to R&D

The time tracking constitutes an important subject as well. The administration can align the declared times with the company’s time-tracking system, with actual working time, with HR absences, with job descriptions, and with the technical elements that document the work performed.

The partial scores, Since the collaborators do not point to all their activities, certain particularly high or low R&D rates, as well as the profiles of management, project management or support, may trigger additional requests.

There is no single method of proof imposed to justify the timeframes. The issue is produce a coherent and sufficiently robust demonstration in light of the reality of the activities carried out.

Also read: Justification of CIR time: how to prove the time spent on R&D?

What role does the supporting document play during a CIR check?

The documentation must allow an external party to the company to understand Why the work is considered R&D and how the declared expenses relate to it.

This requirement becomes particularly important when a scientific expert is involved. The The quality of the dossier’s structuring appears to be a factor that directly facilitates analysis.. An expert works largely based on the documents that are provided to him/her: the file must therefore allow him/her to understand the operations without having previously known the company or its projects.

However, a robust supporting dossier does not solely rely on a document written at the time of the declaration. The technical elements produced during the work, the traces of the teams’ involvement, and the data that can be used to link time and costs also contribute to the demonstration.

That is why it is better to Capitalizing on the documentation as it develops rather than trying to reconstruct the course of a project several years later.

To be read soon: CIR supporting file: how to build solid evidence?

Is it mandatory to use a time tracking tool for the CIR?

No specific software is required as a condition of eligibility for the CIR.

On the other hand, the company must be able to justify the personnel costs that it values and to demonstrate the reality of their participation in R&D operations.

A structured monitoring system can facilitate this demonstration, especially when it allows to bring the project- or activity-specific timeframes closer to the HR data and the available technical elements.

The important question is therefore not just « Do you have a tool?», But also: how are the times reported, verified and validated? What granularity is used? How are absences or time off from the project taken into account?

It is precisely this overall coherence that can be examined. Our experts warn of the need for a precise, rigorous and reliable monitoring as well as the comparison between the points in time, HR data and physical evidence.

Do you want to strengthen the mastery of the CIR/CII within your teams?

Our training « Securing and managing your CIR / CII: mastering the mechanisms and anticipating tax controls » It is addressed in particular to DAFs (Directorates of Finance, Legal and Research and Development), R&D and Innovation departments and managers involved in the management of the schemes.

Discover the CIR/CIR training

How to prepare before a possible CIR tax inspection?

Preparing an audit does not consist in producing more documents for each operation, but in being able to quickly finding coherent and relevant elements when the administration asks a question.

This involves, among other things, documenting operations during their execution, regularly reviewing their eligibility, aligning R&D, HR, accounting, and tax data, and identifying areas that may be more difficult to defend.

Our experts propose a particularly pragmatic approach: put yourself in the position of the auditor and ask yourself: Which elements of the file would naturally raise a question and which supporting documents would answer it?. This analysis can, in particular, make it possible to identify in advance an operation whose scientific qualification is less obvious, an atypical rate of R&D, insufficient documentation, or expenses whose connection to the project must be explained.

What to do when a CIR tax inspection begins?

The first step is to identify precisely the procedure initiated and the nature of the requests made by the administration.

The responses must then be coordinated between the various relevant departments. A question concerning scientific eligibility will primarily require the intervention of the R&D teams; an inquiry regarding the amounts valued will require the involvement of the financial or fiscal departments more extensively.

This coordination avoids, in particular, transmitting elements that are technically accurate but inconsistent with the accounting, HR or reporting information already communicated.

In the event of disagreement with the administration, it is also essential to identify the nature of the point in dispute: technical, financial or procedural. The possibilities of appeal are not the same depending on the situation.

To be read soon: CIR Restructuring: what remedies are available to challenge a rectification?

Who should be involved in the management of the CIR control?

The CIR is fiscal, but its justification is necessarily cross-cutting.

The R&D or Innovation direction has knowledge of the work and must be able to explain the scientific or technical issues encountered.

The Financial direction helps ensure consistency between declared expenses, accounting data, and HR information.

The tax or legal department He/She masters the framework of the procedure, the exchanges with the administration and the procedural aspects.

This coordination should ideally be structured before the audit. It is more broadly part of a governance framework for the taxation of innovation, integrating CIR, CII, intellectual property, and, where relevant, IP Box.

To go deeper into this cross-cutting approach: CIR, CII and IP Box: building a successful and secure tax strategy for innovation

CIR, CII, IP Box tax control: deepen the subject in a replay

This topic was the subject of a dedicated webinar hosted by Maxime Mancier, expert consultant in innovation taxation, and François-Xavier Pic, tax lawyer, Around the main grounds of challenge observed, the different types of control, scientific expertise, the IP Box and the avenues of appeal.

The replay is a good complement to deepen the insights presented in this article.

Watch the replay of the CIR, CII, IP Box tax control webinar

Would your CIR be easily defensible in the event of an inspection?

In the face of an audit, the key issue is being able to explain the declared operations and to quickly produce the elements necessary to justify the expenses incurred.

The scientific and fiscal experts of G.A.C. Group we have been assisting companies for nearly 25 years in reviewing their practices, preparing their documents and conducting their exchanges with the administration.

Make an appointment with our experts

FAQ – CIR tax control

What is a CIR tax inspection?

This involves the administration verifying the validity of the Research Tax Credit declared by the company. The review can focus on the scientific eligibility of R&D operations as well as the justification of the expenses included in the tax base.

What documents can be requested during a CIR check?

The requests depend on the file. They may concern the technical documentation of R&D operations, the elements related to the personnel valued, the time spent on work, the accounting and HR documents, as well as the evidence demonstrating the contribution of the employees to the projects.

Can the administration call on a scientific expert to monitor the CIR?

Yes. The ministry responsible for Research can intervene in the control of the scientific and technical eligibility of declared operations. The analysis of R&D activities is based, in particular, on the concepts defined by the Frascati Manual and reproduced in the CIR Guide.

Is a time tracking software mandatory to benefit from the CIR?

No. No specific software is required as the only means of proof. However, the company must be able to coherently justify the involvement of its personnel and the expenses it declares. Time tracking is one of the means used to ensure this traceability.

How long can a CIR tax inspection last?

There is no single duration applicable to all CIR checks. The deadlines depend, among other things, on the procedure, the complexity of the file, the exchanges with the company, and any scientific expertise that may be required.

How can the risk of the CIR being called into question be limited?

The robustness of the dossier relies, in particular, on the regular qualification of R&D operations, the documentation being kept up to date, the traceability of activities and expenses, and the consistency between technical, HR, accounting and tax information.

Article written by Agathe Courteille, Marketing Manager of Innovation offers at G.A.C. Group, based on the feedback and analyses of François-Xavier Pic, Head of Legal and Tax Affairs, and Maxime Mancier, Expert Consultant in Innovation Tax.

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