R&D base (S&O-grondslag)

Definition

The R&D base (S&O-grondslag) is the amount over which RVO calculates your WBSO benefit. It consists of the granted R&D hours multiplied by the R&D hourly wage — either the average hourly wage of your R&D staff or the flat-rate wage — plus any additional costs and expenditure attributable to the R&D project, such as materials or equipment. A tiered rate applies to this base: in 2026 you receive 36% on the first €391,020 and 16% on the remainder, with an increased 50% rate in the first bracket for starters. The higher the base, the larger the absolute benefit, even though the percentage drops above the first bracket. The base is estimated at the time of application and, after the calendar year ends, compared with the hours and costs actually realised through the realisation report, after which RVO determines the final benefit. Because the base is directly tied to both the number of R&D hours and the R&D hourly wage used, accurate hour tracking is essential: underestimating costs you benefit unnecessarily, while overestimating leads to a correction afterwards. Employers and sole traders are treated differently: employers have the benefit settled against payroll tax over the full base, while sole traders who meet the hours criterion receive a fixed deduction instead of a base calculation.

Frequently asked questions

What is the R&D base (S&O-grondslag)?

The R&D base is the amount over which your WBSO benefit is calculated: the granted R&D hours multiplied by the R&D hourly wage, plus any costs and expenditure.

What rate applies to the R&D base in 2026?

In 2026, 36% applies to the first €391,020 of the R&D base and 16% to the remainder; starters receive 50% instead of 36% in the first bracket.

Why does an accurate R&D base matter?

An inaccurate estimate of the base leads to a lower benefit or a correction at the realisation report stage, so accurate hour tracking is essential.