Applying for WBSO in 2026: a step-by-step guide for SME owners

Key points: The WBSO (Wet Bevordering Speur- en Ontwikkelingswerk, the R&D Tax Credit Act) is, with a EUR 1.8 billion budget, the largest innovation subsidy in the Netherlands. Success rate >95% with solid substantiation. You apply monthly, by the last day of the month before the desired period (for a 1 January start, by 20 December). Employers may file a maximum of 4 applications per year; self-employed professionals have no limit. The reduction works through payroll tax: you remit less payroll tax to the Tax Authority (36% reduction standard, 50% for starters). This guide takes you from idea to filed application in five concrete steps.

What the WBSO covers exactly

The WBSO compensates R&D wage costs and other R&D costs. These are:

• Research: technical research whose outcome is still uncertain.
• Development work: technically new (for your company) products, processes or software.

In practice, R&D for SMEs includes:

• New software architecture or modules
• Training, evaluating and deploying machine learning models
• Data pipeline and ETL engineering on new data
• AI integrations (LLM APIs, custom prompts, agent workflows)
• Prototypes of hardware or IoT solutions
• Developing algorithms for optimization, prediction, classification

Not WBSO-eligible: standard website building, bug fixes, configuring existing SaaS, content management, marketing work, regular maintenance.

Step-by-step: from idea to filed application

Step 1: Identify your R&D projects (week 1)

Review all development activities internally. For each technical project, answer:

1. Is this new for my company? (technically new = never built before, also not by others as far as known)
2. Are we solving a technical problem? (not "what is nice design?" but "can this ML fit do better than the baseline?")
3. How many R&D hours do we expect? (per developer, per project, per WBSO period)

Make a list of 1-5 R&D projects. More than 5 becomes impractical to administer.

Step 2: Write the project description (week 2)

For each project you deliver a 600-800 word technical description. RVO looks at:

• Technical novelty: why is this not "standard"? What could we not do before?
• Technical problem: which uncertainty are you resolving?
• Approach: how will you remove that uncertainty? Which methods, which iterations?
• R&D activities: training models, building prototypes, running experiments, evaluations.
• R&D hours: estimate per employee per project.

Tip: avoid marketing language. Write for a technical assessor. "We're building an AI-powered dashboard" says nothing. "We train a gradient-boosted tree model on 18 months of order data to forecast volumes per SKU per week with a MAPE improvement over the current naive moving-average baseline" says everything.

Step 3: Calculate the expected benefit (week 2)

The WBSO reduction is calculated as a percentage of R&D wage costs.

• Standard: 36% of the wage costs for R&D hours
• Starter (companies that have existed <5 years and have applied for WBSO <3 years): 50% over the first EUR 391,020 of R&D wage costs
• Above bracket 1 (EUR 391,020+ R&D wage costs): 16%

Example for an SME with 3 developers:

• Wage costs per developer (gross): EUR 70,000/year
• Expected R&D hours: 60% of working time = ~1,000 hours/year
• R&D wage costs: 3 x EUR 70,000 x 60% = EUR 126,000
• WBSO reduction (36%): EUR 45,360/year

Step 4: File via Mijn RVO (week 3)

Applications are submitted online via Mijn RVO. You provide:

• Project description(s), uploaded as PDF
• Planned R&D hours per project, per employee (where possible)
• Estimate of other R&D costs (only relevant above a certain threshold)
• Declaration that the work takes place in the Netherlands
• Recent annual accounts (RVO checks whether you are a company that can carry out R&D)

Crucial deadlines: you file monthly, by the last day of the month before the month your R&D period starts. A few examples:

Employers may file a maximum of 4 applications per calendar year; self-employed professionals have no limit.

Step 5: Assessment + hour administration (week 4+)

RVO assesses within 13 weeks. You receive an S&O declaration (R&D declaration) with:

• Awarded R&D hours per project
• The WBSO percentage you are entitled to
• Send the S&O declaration to your payroll administration/Tax Authority, so that you remit less payroll tax.

From then on the administration continues. You keep track, per employee per day, of how many R&D hours they spent on which project. Each quarter you report this via Mijn RVO. Tools such as Toggl, Harvest or a simple Excel suffice.

Audit risk: RVO carries out spot checks. Keep timesheets and be able to substantiate what was an R&D hour versus regular work. When in doubt: note per hour which technical uncertainty you investigated that hour.

Ten pitfalls to avoid

1. Too vague a project description: RVO wants a concrete technical challenge, not a business ambition.
2. Too broad a scope: one project per actual technical uncertainty; not "our entire 2026 plan".
3. Forgetting that you file by the last day of the month before the period: a common reason for rejection.
4. Not tracking hours: you'll run into problems during an audit.
5. Claiming WBSO on marketing/management/sales: doesn't work.
6. Underestimating starter status: if you qualify, write it explicitly in the application.
7. Not stacking with MIT: WBSO + MIT combined can cover up to 50%+.
8. Claiming foreign R&D: only work in the Netherlands counts.
9. Not accounting for wage tax exemption: if payroll tax is already low, the reduction is limited.
10. Applying just once: WBSO works best as an ongoing strategy. Apply per quarter for optimal cash flow.

The fast route via Stratalytic

We write WBSO applications for SMEs and then build out the R&D work. Three reasons why this is faster and more certain:

• Technical assessor perspective: we know exactly which wording RVO is looking for.
• End-to-end: we handle both the application and the development. No handover losses.
• Combination with MIT and SLIM: if WBSO is not enough, we top it up directly.

Schedule a 30-minute introductory call, we'll check whether your projects qualify and what the expected WBSO return is.

Frequently asked questions

When is the latest I can apply for WBSO? You apply monthly, by the last day of the month before the month your R&D period starts. For a 1 January start, the application must be in by 20 December. Employers may file a maximum of 4 applications per year; self-employed professionals have no limit. Filing too late means the next period.

What if I don't yet know how many development hours I'll make? You provide a realistic estimate per project. Afterwards you report the actual hours via Mijn RVO.

Can existing software development qualify for WBSO? Only the part that is technically new for your company. Standard maintenance and routine features do not count. R&D on new modules, models or architecture does.