Flat rate (WBSO)

Definition

The flat rate (forfait) is a simplified way of accounting for the costs and expenditure of a WBSO project: instead of tracking and documenting every individual cost item, you apply a fixed surcharge of €10 per R&D hour on top of your wage costs. This flat rate is meant to cover costs and expenditure such as materials or small tools used during research and development, without the administrative burden of itemising each expense. The alternative is reporting the actual costs and expenditure, supported by full documentation — an approach that tends to pay off when a project's real material or equipment costs clearly exceed what the flat rate would produce, for example in capital-intensive manufacturing or biotech development. You must choose one of the two options per calendar year, and you cannot switch between the flat rate and actual costs within the same project year — mixing them is one of the more common mistakes companies make when calculating their WBSO benefit. Whichever option you pick becomes part of your S&O wage base, alongside your R&D wage costs, and is settled through the same payroll tax reduction or, for sole traders, the same fixed deduction. Choosing correctly between the flat rate and actual costs is therefore a small but consequential decision that is worth revisiting each year as your project's cost structure changes.

Frequently asked questions

What is the WBSO flat rate (forfait)?

The WBSO flat rate is a fixed surcharge of €10 per R&D hour that covers your project's costs and expenditure, so you don't need to administer each cost item separately.

Can you switch between the flat rate and actual costs during a project?

No — you choose one of the two per calendar year, and you cannot mix the flat rate with actual costs and expenditure within the same year.

When is it better to report actual costs instead of the flat rate?

Reporting actual costs and expenditure tends to be worthwhile when your real material or equipment costs clearly exceed what the flat rate would produce, such as in capital-intensive projects.