When must you submit your declaration?
In general, you have until the last day of the seventh month following the end of the financial year to submit your declaration.
If the deadline for submission falls on a Saturday, Sunday, or public holiday, an extension is granted until the next working day.
For declarations with balance dates from 31 December 2024 to 28 February 2025, the deadline for submission has been set at 30 September 2025.
The models of the declaration forms for corporate tax and legal entities tax, as well as for the tax on non-residents/companies for the assessment year 2025 (income 2024), were published in the Moniteur belge on 22 April.
Receive your refund faster
Individuals who submit their declaration by 29 August 2025 can also expect a benefit. These declarations will be processed preferentially, allowing for a faster refund, which will be issued by the end of December 2025 at the latest (unless exceptions apply).
Source