Belgian companies with a research or development department can deduct up to 80% of the withholding tax on R&D wages and cannot pay it to the tax authorities. Those who want to claim it must be able to prove their hours.
In this article, you can read who qualifies, what the tax authorities control and how to organize time registration conclusively.
The most important insights
- The exemption amounts to 80% of the withholding tax to be paid on qualifying wages. The employee's net salary remains unchanged — the benefit lies entirely with the employer.
- Both diploma and project determine whether an employee qualifies. Only researchers with a recognized scientific diploma and who are actively involved in an R&D project fall under the scheme.
- The exemption is not automatic - you actively apply for it via the withholding tax return. If the required documentation is missing during an audit, the tax authorities will recover the full benefit.
- Time registration per employee and project is the core of the evidence. Without a demonstrable amount of time spent on R&D, you are legally weak.
- Software development with technical innovation is explicitly covered by the regulation. Routine maintenance and bug fixes without new knowledge are excluded.
- Combining with the innovation allowance is possible, but requires separate documentation. Both measures use their own calculation basis.
- An Excel file filled in afterwards is not sufficient as proof. The tax authorities expect real-time or weekly registered hours.
What is the withholding tax exemption for R&D?
Employers who employ R&D staff are not allowed to pay part of the withheld withholding tax to the Belgian Treasury. The employee's net salary does not change. The benefit directly reduces the employer's wage costs.
The measure is laid down in Article 275/3 of the CIR 92 and is managed by the FPS Finance.
📌 The percentages and conditions in this regulation may change due to new legislation or Royal Decrees. Keep an eye on this blog for updates, or check out the FOD Finance for the most up to date information.
What percentages apply in 2026?
Note: these percentages are subject to change. Check the current rates via FOD Finance. In all categories, an exemption of 80% applies. The categories are:
- Standard R&D - employee with a recognized scientific diploma, active on a qualifying project
- Young Innovative Company (YIC) - young companies that meet specific turnover and R&D expenditure criteria
- Cooperation with university or recognized research center - project runs in cooperation with a recognized institution
- Fundamental research - carried out by or in cooperation with a recognized research institution
The percentages are the same, but the admission requirements for each category vary considerably. The right category determines which documentation you need.
Who qualifies?
The degree and project requirements that determine whether you can claim the exemption.
Employee conditions
The employee must meet one of the following diploma conditions:
- Holder of a master's degree in exact sciences, applied sciences, computer science or medicine.
- Holder of a bachelor's degree in the same fields, provided that they are employed in a position that requires that training.
- Doctorate (PhD) holder.
- Employed at an approved research center or in cooperation with a university.
⚠️ Important: The Bachelor Ceiling. Since the recent changes in the law, the exemption for bachelor's degrees is no longer unlimited. For large companies, the total amount of the exemption for bachelor's degrees should not exceed 25% of the amount that is exempt for masters/doctorates. For SMEs, this ceiling is 50%. Do you only employ bachelor's degrees? Then you cannot (fully) apply this measure.
The exact list of recognized diplomas is laid down by Royal Decree and can be updated. Consult FOD Finance or your social secretariat for the current list.
What can you do now?
- Make an inventory of R&D staff and verify their diplomas against the approved list.
- Calculate the ratio between your masters and bachelor's degrees to see if you exceed the “bachelor ceiling”.
- Assess for each ongoing project whether it meets the EU definition of industrial research or experimental development.
- Formally record the project description - an internal project letter or technical memo is a good starting point.
Project conditions
The employee must be actively involved in an R&D project that meets the EU definition. The tax authorities now strictly test this on the basis of the Frascati standard.
A project only qualifies if it meets five criteria: Novelty, Creativity, Uncertainty, Systematics and Portability.
- Fundamental research: Original theoretical or experimental work with no direct commercial purpose.
- Industrial research: Planned research focused on new knowledge for products or processes.
- Experimental development: Translating research results into new or improved products.
Crucial in 2026: Routine maintenance, bug fixes, and standard project implementations are not covered by the regulation. There must be a solution to a technical uncertainty. It does include new algorithm design or the development of technically innovative software components that go beyond the current state of the art.
What can you do now?
- Make an inventory of R&D staff and verify their diplomas against the approved list.
- Assess for each ongoing project whether it meets the EU definition of industrial research or experimental development.
- Formally document the project description — an internal project letter or technical memo is a good starting point.
How do you apply for the exemption?
The exemption is not granted automatically. You process them via the withholding tax return (form 274) that you submit monthly or quarterly to the FPS Finance. Note: this is only allowed after the project has been formally registered.
Practical steps
- Report your project or program to Belspo (Programmating Federal Science Policy). This is an absolute condition; without a valid registration number, you cannot apply the exemption.
- Identify qualifying employees and projects for the declaration period. Make sure that the start date of the work falls after the date of the Belspo registration.
- Calculate the withholding tax deducted from the qualifying wage mass.
- Apply the exemption rate to that amount.
- State the exempt amount in the declaration (including the Belspo number received) and only pay the remaining part.
Note: You book the benefit in the same period as the wage payment. Correcting a forgotten period afterwards requires a formal appeal procedure. In addition, the exemption is not retroactively valid for hours worked. before the Belspo registration.
What can you do now?
- Make sure that all your ongoing R&D projects are registered correctly in the Belspo portal.
- Agree with your social secretariat or accountant whether the exemption is being processed correctly and whether the Belspo number is included in the return.
- Check historical returns — companies with R&D activities that don't claim the exemption yet are losing money.
- In case of doubt, request binding advice from Belspo about the substantive qualification of your project (the Frascati test).
The exemption is not granted automatically. You process them via the withholding tax return (form 274) that you submit monthly or quarterly to the FOD Finance.
How do you apply for the exemption?
The exemption is not granted automatically. You process them via the withholding tax return (form 274) that you submit monthly or quarterly to the FOD Finance.
Practical steps
- Identify qualifying employees and projects for the declaration period.
- Calculate the withholding tax deducted from the qualifying wage mass.
- Apply the exemption rate to that amount.
- State the exempt amount in the declaration and only pay the remaining part.
Please note: you book the benefit in the same period as the wage payment. Correcting a forgotten period afterwards requires a formal appeal procedure.
What can you do now?
- Agree with your social secretariat or accountant whether the exemption will be processed correctly.
- Check historical returns - companies with R&D activities that don't claim the exemption yet are wasting money.
- Request confirmation FOD Finance if you are unsure about the qualification of a project or diploma.
Why time registration is the core of the evidence
The FPS Finance checks the exemption on the basis of two questions: who worked on R&D and how much time was spent doing so? You must answer these questions with concrete figures per employee, per project, per period.
The financial risks of a weak file
The tax authorities have become stricter: in the event of poor administration (such as ex-post estimates), the full exemption is often rejected. This leads to:
- Chargeback of the full benefit enjoyed.
- Negligence interest: These are variable and in line with the market (expect a significant percentage per year in 2026).
- Tax increases: These range from 10% to 50%, and can be even higher in case of repetition or bad faith.
An Excel file that has been filled out afterwards based on memory does not count as reliable evidence. The tax authorities expect a simultaneous registration (real-time or weekly) that reflects the actual hours worked.
What can you do now?
- Set a guideline that R&D hours are recorded daily or weekly.
- Test your projects against the 5 Frascati criteria: is there really a technical uncertainty you're trying to solve?
- Make sure your time registration system distinguishes between R&D and other activities — at project and task levels.
- Archive quarterly timesheets together with the project file and Belspo registration.
Combining with the innovation allowance: what is allowed and what is not
You can apply two measures side by side, but requires separate files. The exemption from withholding tax and the innovation deduction are separate measures that can be applied side by side.
The two measures work as follows:
- Exemption from withholding tax - based on the wage costs of qualifying R&D staff. The benefit is 80% of the withholding tax to be paid.
- Innovation deduction - based on net innovation income from patents or copyrighted software. The benefit is an 85% deduction on the taxable profit.
One time registration for both requests is not sufficient. The calculation bases and evidence requirements are different.
💡 The combination rules and percentages may change. Consult FOD Finance or a tax advisor for the current situation, or keep an eye on this blog for updates.
TimeChimp helps you register R&D hours in a fiscally watertight manner
For example, TimeChimp supports you in providing evidence to the FPS Finance.
- Time registration per project and task: employees log hours directly to the R&D project — exactly the structure that the FPS Finance expects.
- Reports by employee and period: export quarterly hourly statements for use in your tax file.
- Real-time registration via mobile and desktop: no more end-of-month estimates.
- Project management with budget control: keep track of how much capacity is actually spent on research.
- Integration with your payroll administration: link hour statements to your salary processing to correctly calculate the exempt wage mass.
Conclusion
The exemption is valuable, but only for those who have their records in order. The R&D exemption for withholding tax is one of the most valuable tax measures for Belgian IT and consultancy companies. But those who claim without a conclusive time registration risk full recovery plus fines.
The conditions are clear: the right diplomas, the right projects, and a registration that shows who spent how much time what. Organize that now, not afterwards.
Key deadlines
- Monthly/quarterly: process the exemption in form 274
- Annually: update project files and align them with the financial statements
- When checked: have quarterly timesheets available, including project descriptions and diploma certificates
👉 Do you want to register R&D hours in a way that passes a tax audit in Belgium? Start a free trial
FAQs
The exemption is deducted from the periodic withholding tax return (form 274). The employer withholds the withholding tax but only pays 20% to the FPS Finance. Required are: a job description per employee, proof of the qualifying diploma, and a time record that shows that the 80% limit for R&D work has been reached.
Employees must have a master's degree in an exact or applied scientific field and must spend at least 80% of their working time on qualifying R&D work. In 2026, bachelor holders and employees without a diploma can also qualify if they work in a research program recognized by Belspo. Time use must be demonstrated with a substantiated time registration.
The R&D withholding tax exemption allows Belgian employers not to pay 80% of the withholding tax deducted from the salaries of qualifying R&D employees to the tax authorities. The measure is laid down in article 275/3 WIB 92. In 2026, the exemption rate will remain 80%.
