The extension is limited to 30 June 2026, except for deadlines within three months of that date, with up to 40% deduction rates for sustainable transition investments.
Belgium’s Federal Public Service for Finance has published the royal decree of 28 July 2025 in the Official Gazette on 12 August 2025, which extends the deadline to apply for a certificate of entitlement to the Belgian increased thematic investment deduction to 12 months after the end of the taxable period or financial year.
However, the extension cannot exceed 30 June 2026, except if the regular deadline falls within three months of that date. Deduction rates of up to 40% are available for sustainable transition investments.
The deadline was extended due to the delayed formation of the new government, which postponed the launch of the new investment deduction application system. The royal decree extends the deadline for certificate requests under the thematic deduction, but uncertainty remains for companies with non-calendar financial years that invested in 2025.
Since certificate requests for the thematic deduction cannot yet be submitted, and guidelines are still pending, these companies must rely solely on the published lists of eligible investments when filing their 2025 corporate tax returns.
Earlier, Belgium’s Federal Council of Ministers approved royal decrees to reform the investment deduction regime, introducing three categories of investments that are eligible for additional tax deductions, which took effect on 1 January 2025.
Under the decrees, small companies and eligible individuals now receive a basic 10% deduction. Additionally, there is an “increased thematic deduction” of 30% for large companies and 40% for small companies and individuals.
