How to Write a Grant Budget Justification in Belgium
Step-by-step guide to writing a grant budget justification for Belgian programs — personnel costs, equipment, subcontracting, overhead, and co-financing rules.
Why the budget makes or breaks your application
Most Belgian grant applications are not rejected because the idea is bad. They are rejected because the budget is poorly structured, unrealistic, or inadequately justified. Grant evaluators at VLAIO, Innoviris, and SPW scrutinise your cost breakdown as closely as your project narrative.
A well-justified budget demonstrates that you understand the true costs of your project, that you have realistic expectations about timelines and resources, and that you can manage public funds responsibly. It also shows you have read the program guidelines carefully — each agency has specific rules about what counts as an eligible cost.
This guide walks you through the main budget categories, explains what each agency expects, and highlights the common mistakes that lead to rejections or budget cuts. If you want help structuring your grant application, use Lucas, BelGrant's AI assistant, to get started.
Personnel costs — the biggest line item
Personnel costs typically represent 60% to 80% of a Belgian grant budget. VLAIO, Innoviris, and SPW all accept personnel costs but calculate them differently. VLAIO uses standardised hourly rates based on salary bands, while Innoviris often requires actual salary costs plus employer contributions.
You must justify each team member's role, their time allocation to the project (as a percentage of full-time equivalent), and why their expertise is necessary. Generic descriptions like "project manager — 50% FTE" are not enough. Specify what they will do, which work packages they contribute to, and why their seniority level is appropriate.
Common mistakes include overestimating FTE allocation (evaluators compare your team size to similar projects), including staff who have no clear role in the project, and forgetting to account for part-time workers or contractors differently from full-time employees.
Equipment, subcontracting, and other direct costs
Equipment costs cover machinery, software licences, lab equipment, or specialised tools needed for the project. Most Belgian programs only accept the depreciation cost for the project duration, not the full purchase price. If you buy a €50,000 machine and your project lasts 2 years out of a 5-year useful life, you can only claim €20,000.
Subcontracting is allowed but typically capped at 30% to 50% of the total budget. VLAIO limits subcontracting to tasks that cannot reasonably be done in-house and requires you to justify why external expertise is needed. Innoviris has similar restrictions. Always specify the subcontractor's role, expected deliverables, and cost basis.
Other direct costs — travel, consumables, prototyping materials, IP filing — must be individually justified and directly linked to project activities. Vague line items like "miscellaneous — €10,000" will be rejected. Be specific: "Patent filing for product X in BE/EU — €8,000 based on quote from patent attorney."
Overhead and co-financing rules
Overhead (indirect costs) is handled differently by each agency. VLAIO typically applies a flat-rate overhead of 20% on top of personnel costs. Innoviris may allow actual overhead or a flat rate depending on the program. SPW programs in Wallonia have their own overhead calculation methods.
Co-financing is a critical concept. Most Belgian grants do not cover 100% of project costs. VLAIO SME innovation grants cover up to 45% for small enterprises, meaning you must fund the remaining 55% yourself. This own contribution can come from cash, in-kind contributions, or other (non-public) funding sources.
Document your co-financing sources clearly. If you claim own resources, show that your company has the cash flow or credit lines to support the project. If you plan to combine grants, make sure there is no double funding — Belgian agencies actively check for this and will reject or claw back overlapping subsidies.
Common budget mistakes and how to avoid them
The most frequent budget mistakes in Belgian grant applications are: inflated personnel costs (claiming senior rates for junior tasks), undocumented subcontracting, missing depreciation calculations for equipment, and no clear link between costs and work packages.
Another common issue is ignoring the agency's budget template. VLAIO, Innoviris, and SPW each provide specific templates with predefined categories. Using a different format or adding non-standard categories creates friction and signals that you have not read the guidelines.
Finally, always build in a realistic contingency. While you cannot add a "contingency" line item, you can ensure your estimates include realistic buffers. Get actual quotes for subcontracting, check current salary benchmarks, and use recent pricing for equipment. Under-budgeting is as problematic as over-budgeting — it suggests you do not understand the scope of your own project.
FAQ
What percentage of a Belgian grant budget should be personnel costs?
Personnel costs typically represent 60% to 80% of the total budget in Belgian grant applications. This varies by project type — R&D-heavy projects tend toward the higher end, while investment-focused grants have more equipment costs.
Can I include overhead in a VLAIO grant budget?
Yes. VLAIO typically applies a flat-rate overhead of 20% on top of personnel costs. You do not need to justify individual overhead items — the flat rate is applied automatically. Innoviris and SPW may use different overhead methods.
What happens if my grant budget is cut during evaluation?
Evaluators may reduce specific budget lines if they find costs insufficiently justified or inflated. This reduces the total grant amount but does not necessarily reject your application. You can often negotiate or provide additional justification during the evaluation process.
Grants mentioned in this article
Explore these funding programs in detail on BelGrant: