Corporate Income Tax Return (Biztax)
Annual corporate income tax return for Belgian companies, filed electronically on Biztax through the MyMinfin portal by the last day of the 7th month after the financial year-end.
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Who this applies to
- Belgian companies subject to corporate income tax (SRL, SA, SC)
- Companies with a 31 December year-end, for which the date is 30 September
What to file
The corporate income tax return for the financial year, with the company's taxable profit and any reliefs claimed, such as the SME reduced rate or the Notional Interest Deduction.
How to file
Electronically on Biztax, reached through MyMinfin. Filing by 28 August for a December year-end speeds up refund processing. AccountsOS does not file on Biztax.
Payment due
Any tax due follows the assessment. Advance payments during the year may reduce what is due at assessment (see the advance corporate tax payments deadline).
Penalties for missing this deadline
Late filing is a missed statutory date. Confirm the current consequences with FPS Finance or your accountant.
Filing checklist
- Approve the annual accounts and confirm the taxable result
- Check whether the SME reduced rate conditions are met, including the €50,000 director remuneration condition from tax year 2026
- Work out any Notional Interest Deduction
- Sign in to MyMinfin and open Biztax
- Submit the return and keep the receipt
Documents you'll need
- Annual accounts for the financial year
- Trial balance and tax adjustments
- Director remuneration records
- Equity movements for the Notional Interest Deduction
Common mistakes to avoid
- Assuming a 25% rate without checking the SME reduced rate conditions
- Missing the new €50,000 director remuneration condition for tax year 2026
- Treating the weekend or holiday rule as automatic for other deadlines, such as quarterly VAT
- Leaving the return until the last day when a refund is expected, instead of filing by 28 August
Never miss a Belgium deadline
AccountsOS tracks every FPS Finance (SPF Finances / FOD Financiën) and Crossroads Bank for Enterprises (BCE/KBO) deadline and reminds you weeks ahead.
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