Belgian tax life runs on a tight calendar. Miss one deadline and the penalties compound fast. Here are the 2026 dates every IT consultant should have in their calendar.
Personal income tax
| Deadline | Filing |
|---|---|
| 15 July 2026 | Online (Tax on Web) declaration for income year 2025 |
| End of June 2026 | Paper declaration for income year 2025 |
Quarterly VAT
| Quarter | Declaration and payment deadline |
|---|---|
| Q4 2025 | 10 April 2026 (incl. Christmas tolerance) |
| Q1 2026 | 10 April 2026 |
| Q2 2026 | 10 July 2026 |
| Q3 2026 | 10 October 2026 |
| Q4 2026 | 20 December 2026 (advance) and 20 January 2027 |
Self employed social security
Quarterly: 31 March, 30 June, 30 September and 31 December 2026.
Advance ISOC payments
To avoid the 6.75% penalty, advance payments should land by 10 April, 10 July, 10 October and 20 December 2026, in decreasing weighted importance.
Annual accounts
SRL annual accounts must be filed with the NBB within 30 days of approval by the general meeting, and at the latest 7 months after year end.
Under BSH
Under BSH umbrella payroll, all of these obligations are handled automatically on your behalf. The only thing left in your calendar is the personal IPP declaration.
This article is for informational purposes only. Consult a certified accountant for personalised fiscal advice.