The WBSO is one of the most valuable subsidies for innovative companies in the Netherlands. In 2026, there will be no less than €1.817 billion available - and yet many companies are leaving money behind. Not because they don't innovate, but because they make mistakes in the application or administration. We list the five most common mistakes, including how to prevent them.
The most important insights
- The WBSO reimburses 36% of your S&O wage costs up to €391,020. For starters, that's even 50%.
- Errors in time registration are the most common reason for recovery by the RVO.
- You can only apply for the subsidy for future work, retroactive effect does not exist.
- A project description that is too vague without a technical basis almost always leads to rejection.
- The realization report must be submitted no later than 31 March after the end of the grant year.
- With the right tooling, a WBSO-proof administration is easy to maintain - without extra workload.
What is the WBSO again?
The Research and Development Work Promotion Act (WBSO) is a tax regulation that significantly reduces the wage costs for R&D employees as a company. You pay less payroll tax on the hours your employees spend on innovation projects.
The scheme is accessible to:
- Companies with payroll staff
- Self-employed persons (freelancers) who carry out R&D work
- Startups as well as established companies
The benefit in 2026:
- 36% discount on wage and R&D costs up to €391,020 (first instalment)
- 16% over the excess (second drive)
- 50% for starting companies (first instalment)
📚 Here you can read everything about the WBSO and how TimeChimp helps you
The 5 most common mistakes
Below are the top 5 most common mistakes in WBSO administration.
Mistake 1: Hours are not recorded (on time)
This is by far the most common mistake — and the most dangerous. S&O employees do not keep track of their hours, only register afterwards or write down hours globally without a project link.
Why this is going wrong:
- Employees forget to keep track of it every day
- There is no system that makes registration easy
- Hours are estimated back at the end of the week or month
What the RVO expects: The hours must be set per person, per day and per project - and be demonstrable when the RVO carries out an audit. Can't you prove that? This is followed by recovery of the subsidy received.
How to prevent this: Provide a digital time registration system where employees enter their R&D hours per project every day. Easily register your hours via the app or desktop, directly linked to the right WBSO project. The data is always up to date and can be exported RVO-proof.
Mistake 2: No distinction between R&D work and regular work
An employee works on both innovative projects and regular customer projects. But in the administration, all hours are lumped together - or worse, all hours are listed as S&O.
Why this is going wrong:
- There is no clear project structure in the time registration
- Employees don't know exactly what counts and what doesn't count as an S&O
- Regular engineering work is accidentally included
What the RVO expects: Only hours that contribute directly to the development of something technically new count as S&O, which does not include standard engineering, management or customer support. The distinction must be demonstrable by hour.
How to prevent this: In your time registration system, create separate projects for R&D work versus regular work. Set up a WBSO project structure so that employees immediately choose the right project with every time input. This way, the distinction is always clear - even during an inspection.
Mistake 3: Project description is too vague or functional
The request does describe what is being built, but not why it is technically challenging. The RVO does not assess the functionality of your product, but the technical bottlenecks that you need to solve.
Why this is going wrong:
- The description is written from a product or marketing perspective
- Technical challenges are not specifically identified
- No distinction is made between research and realization
What the RVO expects: A strong request explicitly describes what technical uncertainties exist, why existing solutions are not sufficient and what steps are being taken to solve the problem. The more specific, the better.
How to prevent this: Always write the request from the technical point of view, not from the end product. Have the application checked by someone with a technical background and someone who knows the WBSO criteria well. Use progress notes and interim documentation as evidence.
Mistake 4: Request is submitted after the project has already started
The WBSO is a forward-looking arrangement. You can only apply for a subsidy for activities that have yet to begin. Anyone who only submits an application after the project is already underway is not eligible - no matter how innovative the project is.
Why this is going wrong:
- Companies only discover the WBSO halfway through a project
- The deadline is overlooked
- There is no internal process to prepare applications in a timely manner
What the RVO expects: The application must be submitted before the work starts. The grant period always starts on the first day of the month following submission.
The deadlines for 2026:
- Applications can be made throughout the year, at the latest on the last day of each month
- The subsidy period always runs until December 31, 2026
- Realization report for 2025: no later than March 31, 2026
How to prevent this: Set a fixed time of year to inventory new innovation projects and submit a WBSO application in time. Also, keep track of which new projects are being started in the meantime, so you are never late.
Mistake 5: The realization message is incorrect or forgotten
At the end of the subsidy period, you must report the actual realised R&D hours to the RVO. Many companies forget this, submit it too late or fill it in incorrectly due to errors in the time registration.
Why this is going wrong:
- Hours were not accurately tracked throughout the year
- The realization differs significantly from the request, without being substantiated
- The March 31 deadline is missed
What the RVO expects: The realization report must match the actual hours worked per project. Major deviations without explanation attract attention. And anyone who forgets the report completely risks a fine.
How to prevent this: Keep track of hours throughout the year — not just at the end. With TimeChimp, you can generate a complete overview of the realized R&D hours per employee and per project at any time. For example, the realization report in March is not a time-consuming task, but a matter of exporting.
Summary: 5 mistakes at a glance
- Mistake 1 - Do not register hours (on time) → use a daily time recording tool
- Mistake 2 - No distinction between R&D and regular work → set up separate projects per activity
- Mistake 3 - Too vague project description → describe technical bottlenecks, not functionality
- Mistake 4 - Request after the start of the project → plan requests in advance, never retroactively
- Mistake 5 - Realization message forgotten or incorrect → export hours automatically before March 31
TimeChimp helps you work WBSO-proof
Correct WBSO administration starts with reliable time registration. With TimeChimp, employees record their R&D hours daily per project, via the app or desktop. Managers see in real time how many hours have been booked per project and can export an RVO-proof for the realization report with one click.
With TimeChimp:
- Record your R&D hours daily, per employee and per project
- Make a direct distinction between R&D work and regular activities
- Export your hours automatically in the correct format for the RVO
- Are you always ready for a check-up - without extra preparation
📚 Here you can read how TimeChimp helps you with a WBSO-proof administration
📌 The WBSO deadlines in this article are based on the latest RVO information for 2026. Always consult rvo.nl or a grant advisor for the most current terms and conditions.
👉 Want to know how TimeChimp helps you get the most out of the WBSO? Start a free trial
FAQs
The RVO requires that R&D hours are kept track of per project, per employee and per working day - real-time, not estimated afterwards. A compliant tool must be able to generate exportable overviews that can be used directly during an audit. In addition, the system must distinguish between R&D activities and regular work.
No. The RVO only accepts time records that are demonstrably maintained in real time — daily or at least weekly, with a time stamp. During an audit, the plausibility is tested against project planning and other sources. Reconstructions afterwards are a common reason for recovery.
If an RVO check shows that the registered R&D hours do not match the actual time spent, the full subsidy for the year in question can be recovered. Retroactive reconstructions are not accepted. Hours must be recorded in real time, in the name of the employee involved, linked to the specific R&D project.
