Belgium R&D Tax Credits and Innovation Incentives Guide

R&D Payroll Withholding Tax Exemption

• The 80% exemption: Companies performing qualifying R&D activities (the "O&O-project" / "projet R&D") can claim an 80% exemption from the payroll withholding tax (bedrijfsvoorheffing / précompte professionnel) on the remuneration of researchers assigned to the R&D project. The exemption applies to: (a) the gross salary of the researcher, (b) limited to the portion of the salary attributed to the R&D project (the "O&O-tijd" / "temps R&D" — the percentage of time the researcher spends on the R&D project), (c) up to a maximum of €25,000–€30,000 per researcher per year (the exemption is capped at 80% of the withholding tax due). The company withholds the wage tax from the researcher's salary but retains the amount instead of paying it to the FOD Financiën / SPF Finances. The exemption is claimed via the quarterly payroll declaration (DMFA/DIMONA).
• Additional 25% for PhDs and advanced degrees: An additional 25% exemption is available for researchers holding a PhD (the "doctoraat" / "doctorat") or an advanced degree in a STEM field (science, technology, engineering, mathematics). The total exemption for a PhD researcher can reach 80% + 25% = 105% of the withholding tax — the company effectively receives a net cash benefit from the researcher's employment. The additional exemption applies for the first 3 years of the researcher's employment in the company (the "startersperiode" / "période de démarrage"). After 3 years, only the basic 80% exemption applies.
• Qualifying R&D projects: The R&D project must be certified by the regional authorities — the Flemish government (VLAIO — Agentschap Innoveren & Ondernemen), the Walloon government (SPW EER — Service Public de Wallonie Économie, Emploi, Recherche), or the Brussels government (Innoviris). The certification process: (a) the company submits a project description to the regional agency, (b) the agency reviews the project against the Frascati Manual criteria (novelty, creativity, uncertainty, systematic approach, transferability), (c) the certification is valid for the duration of the project (typically 1–3 years). The certification is required before the exemption can be claimed.

Innovation Income Deduction (IID)

• The 85% deduction: The Innovation Income Deduction (IID — de "innovatie-inkomstenaftrek" / la "déduction pour revenus d'innovation") allows a company to deduct 85% of qualifying IP income from taxable income. The IID covers: (a) patent income (the IP must be protected by a patent or a supplementary protection certificate), (b) copyright on software (the software must be original and protectable under the Belgian Copyright Act), (c) plant breeders' rights, (d) orphan drug designations. The qualifying IP must be developed by the taxpayer (in-house R&D) — acquired IP does not qualify (the "developer requirement"). The IID is the Belgian implementation of the OECD modified nexus approach under BEPS Action 5 — the qualifying ratio is calculated as: qualifying R&D expenditure ÷ total R&D expenditure × 85%.
• Transitional rules: The IID applies to IP developed after 1 January 2021. For patents existing before 1 July 2016, the old patent income deduction (PID — "octrooi-inkomstenaftrek" / "déduction pour revenus de brevets") continues to apply at the rate of 80–85% depending on the year. For patents filed between 1 July 2016 and 31 December 2020, a transitional regime applies: the taxpayer can choose between the old PID (80% deduction, subject to the nexus ratio) or the new IID (85% deduction, subject to the nexus ratio). The choice is irrevocable for that patent.
• Qualifying IP income: The IID applies to: (a) royalty income (the IP license fees received from third parties and related parties), (b) embedded IP income (the portion of sales revenue attributable to the qualifying IP — the "embodied IP" formula must be documented through a profit allocation analysis), (c) capital gains on the sale of qualifying IP (if the IP was held for at least 2 years), (d) infringement damages (related to qualifying IP). The income must be net of directly attributable expenses (the "net IP income" — royalties minus direct costs).

Investment Deduction for R&D Assets

• The investment deduction (investeringsaftrek / déduction pour investissement): Companies investing in qualifying R&D fixed assets (patents, research equipment, pilot plants, software for R&D) can claim a one-time deduction of the investment value from taxable income. The deduction rate is: (a) 13.5% for large companies (the standard rate), (b) 20.5% for SMEs (the "verhoogde investeringsaftrek" / "déduction pour investissement majorée"). The deduction is calculated on the acquisition or investment value of the qualifying asset (purchase price + directly attributable costs). The deduction is claimed in the tax return for the year of the investment (the "investeringsjaar" / "année de l'investissement"). If the company has insufficient taxable profit to absorb the deduction, the unused portion can be carried forward indefinitely.
• Qualifying assets: The investment deduction is available for: (a) patents and know-how (the "octrooien en knowhow" / "brevets et savoir-faire"), (b) research equipment (laboratory equipment, testing apparatus, computer equipment used for R&D), (c) pilot plants (the "proefinstallaties" / "installations pilotes"), (d) software acquired for R&D purposes, (e) buildings or extensions used exclusively for R&D (the deduction is limited to the construction or renovation cost). The asset must be used for at least 5 years (the "behoudsperiode" / "période de conservation") in the Belgian business.

Regional R&D Grants

• Flanders — VLAIO: The Flemish agency VLAIO (Agentschap Innoveren & Ondernemen) provides R&D grants for: (a) feasibility studies (the "haalbaarheidsstudie" / "étude de faisabilité" — grant of up to 50% of the project cost for SMEs, max €50,000), (b) industrial research (the "O&O-project" / "projet R&D" — grant of up to 50–70% of the project cost, depending on the company size and the research category), (c) experimental development (grant of up to 25–45%), (d) the O&O-bedrijfsovereenkomst (the R&D company agreement — a long-term R&D cooperation agreement with the Flemish government). The grant is subject to EU state aid rules (the General Block Exemption Regulation — GBER).
• Wallonia — SPW EER: The Walloon Service Public de Wallonie — Économie, Emploi, Recherche provides: (a) the "subside R&D" / "O&O-subsidie" — grants for industrial research and experimental development (up to 50–80% of eligible costs), (b) the "convention R&D" / "O&O-overeenkomst" — a multi-year R&D agreement, (c) the "win-WIN" programme — a wage subsidy for researchers employed by SMEs. The grants are available to companies of all sizes, with preferential rates for SMEs.
• Brussels — Innoviris: The Brussels agency Innoviris provides: (a) the "R&D grant" / "O&O-subsidie" — grants for applied research and experimental development (up to 50–90% for SMEs, depending on the project type), (b) the "co-creation" programme — collaborative R&D projects between companies and research institutions, (c) the "DOUBLE" programme — R&D projects in strategic sectors (health, environment, digital). The Brussels grants are available to companies with a Belgian establishment or a permanent establishment in Brussels.

For the full corporate tax framework, see our Corporate Tax Guide →. For the payroll and employment rules for researchers, see our Payroll Tax Guide →. For the pharma and life sciences sector, see our Pharma and Life Sciences Guide →. For the official R&D certification process, see the VLAIO, SPW EER, and Innoviris websites.