AFTER THE APPLICATION · AUDIT
WBSO audit by RVO: what is checked and how do you prepare?
After granting WBSO, RVO can check whether your application corresponds with practice and whether you meet the administrative obligations. The audit can take place via a remote desk audit or at your business location. RVO assesses among others the R&D activities carried out, the realised hours and — with actual costs and expenditures — the amounts made and paid.
BY PETER KLAREN · LAST CHECKED SEPTEMBER 2026 · SOURCE: WBSO GUIDE 2026 (RVO)
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What does RVO check in a WBSO audit?
RVO carries out retrospective audits at companies that have received an R&D declaration. Core of the assessment: does the application correspond with practice, and is that demonstrable?
| Component | What does RVO look at? |
|---|---|
| Application | Do the activities carried out connect with what was approved? |
| Project records | Is the nature, content and progress of the R&D demonstrable? |
| Hours records | Who worked how many hours when on which project? |
| Leave and sickness | Do the registered R&D hours logically connect with these? |
| Actual costs | Were costs granted in advance, made and paid? |
| Actual expenditures | Are investment, use and R&D attribution substantiated? |
| Realisation | Do the reported hours and costs connect with the records? |
In an RVO audit it is not about a perfect file afterwards, but about a credible and verifiable relationship between what you applied for, what was technically actually carried out, which hours and costs belong to it and what was ultimately realised.
Desk audit or on-site audit
RVO can carry out the WBSO audit remotely or at your company on location. In advance you receive notice of the audit, which data RVO wants to receive and within which period you must supply it.
| Desk audit | Company visit |
|---|---|
| Supplying documents digitally | Audit at the business location |
| Remote assessment of the records | Records plus substantive explanation |
| Additional questions possible | Technical employees can provide explanation |
| Preparation of the file is central | Both file and conversations are important |
In both cases: the audit is announced in advance. So you know which documents to supply and when.
Which documents can RVO request in an audit?
Which documents are relevant differs per project. The file must above all convincingly show what actually happened.
Records
Technical evidence
With actual costs and expenditures
More per record type: hours records, project records and costs and expenditures.
Which hours often attract attention?
The job title is not decisive. A director or project manager can only declare R&D hours insofar as he or she personally carries out technically substantive R&D activities within the approved project.
RVO looks at the activities actually carried out, not at the role on paper. Employees not involved in technical substance — for example marketing or secretarial staff — do not deliver R&D hours.
No R&D hours
For the full rules see the WBSO hours records.
Software projects in an RVO audit
In software projects, Git history, issues, technical designs, benchmarks and test results can form very important evidence.
But a large number of commits in itself does not yet prove that R&D was involved. It must also be clear which programming-technical bottleneck was solved and how the technical development proceeded.
See also WBSO software and project records for software.
Product, process and research projects in an audit
Product development
Designs, changes, calculations, prototype logs and test reports make the development process visible.
Process development
Process measurements, test run reports and settings show which technical uncertainty was resolved.
Technical scientific research
Research design, measurement series, interim findings and results together form the research trail.
How do you prepare for a WBSO audit?
- 1Put the application and R&D declaration side by sideWhich activities were exactly approved?
- 2Check the hours recordsPer person, project and day; within the 10-working-day rule; connecting to leave and sickness records.
- 3Check the technical fileIs the development or research chronologically traceable?
- 4Check actual costs and expendituresInvoices, payments, direct attribution and service.
- 5Compare with the actuals reportWere the same totals and projects used?
- 6Identify deviations in advanceWhy did hours, technical approach or planning go differently? A good explanation in advance is stronger than a surprise during the audit.
- 7Ensure someone with technical project knowledge is availableSubstantive questions are best answered by someone who did the work themselves.
RVO-proof file check: can you answer these seven questions with “yes”?
Is any of these answers “no”? Then there is a potential audit point. Preferably resolve that before RVO asks about it.
Connection with the approved R&D activities
The activities actually carried out must recognisably connect with the approved R&D project.
That means not that every experiment must proceed exactly according to the application. New technical bottlenecks, failed solution directions and changes during the development process are not strange — they belong to R&D. The file must however clearly show that the work remained within the approved technical development or research direction.
What happens if RVO finds deviations?
If the audit shows that the WBSO requirements or administrative requirements were not met, RVO can issue a corrected R&D declaration . Previously granted R&D payment reduction can thereby be wholly or partially withdrawn.
| Consequence | Explanation |
|---|---|
| Corrected R&D declaration | The correction can amount to at most the originally granted R&D payment reduction |
| Fine | RVO can, depending on the established violation, impose a fine |
| Processing | The fine is included in the corrected R&D declaration |
More about corrections: Report WBSO actuals.
WBSO audit for self-employed professionals
For self-employed professionals, the 500-hour requirement is especially important. If the audit shows that fewer than 500 qualifying R&D hours were realised, RVO withdraws the R&D declaration.
RVO audit or Tax Administration audit?
These two audits are not the same and are carried out by different authorities.
| RVO checks | The Dutch Tax and Customs Administration checks |
|---|---|
| The content of the R&D project | Payroll tax and returns |
| The realised R&D hours | The fiscal offset |
| The project records | The correct processing of the decision |
| Actual costs and expenditures | The tax-technical application |
Disagreeing with a correction or fine?
You can within 6 weeks of the dispatch date object to the corrected R&D declaration and/or the fine.
Note: you must still process the corrected R&D declaration during the objection procedure. Objection does not automatically suspend that processing.
→ Everything about WBSO objection
→ Received an information notice from RVO?
Frequently asked questions about the WBSO audit
How does a WBSO audit by RVO proceed?
What does RVO exactly check in WBSO?
Which records must I be able to show?
Does RVO always visit for an audit?
Can RVO correct granted WBSO?
Can RVO impose a fine?
What if a self-employed professional realised fewer than 500 hours?
How long do I have to object?
Has RVO announced a WBSO audit?
We test your file in advance, compare application, hours, project records and realisation, and help you make any weak spots transparent before the audit.
SOURCES AND SUBSTANTIVE REVIEW
Reviewed by Peter Klaren, WBSO specialist since 2004. Last substantively updated: 21 September 2026.