Belgian Tax Deadline Extended: 5 Expert Tips to Lower Your Bill

The clock is ticking for Belgian taxpayers. After a technical incident disrupted the Tax-on-web platform on July 10, the Federal Public Service Finance (FOD Financiën) extended the online filing deadline from July 15 to July 19, 2026 — giving Belgians a few extra days to submit their declarations. But with time running out, experts warn that rushing could mean missing out on valuable tax breaks.

According to VRT NWS, approximately 60% of Belgian taxpayers receive a pre-filled simplified declaration (VVA), and a staggering 93% accept it without any modifications. Financial experts say that is a costly mistake. Kenneth De Beckker, Professor of Financial Economics at the Open University and KU Leuven, teamed up with VRT NWS to outline five key areas where taxpayers can still save money before the deadline.

1. Scrutinize Your Pre-Filled Declaration

The single most important step is to carefully review every line of your tax declaration — whether you received a simplified VVA or a standard form. The FOD Financiën confirms that while online declarations are largely pre-filled, taxpayers are responsible for ensuring accuracy.

Check the number of dependents, professional income, alimony payments, and eligibility for tax benefits. “Alles wat niet aangegeven werd terwijl je er wel recht op had, loop je namelijk mis,” the article notes — any benefit not claimed is simply lost.

2. Claim Childcare and Summer Camp Benefits

Parents with young children have a significant opportunity — but also a critical choice to make. A 45% tax reduction is available for childcare costs, including crèche, after-school care, and children’s camps, capped at €16.90 per care day.

However, parents with children under 3 years old (as of January 1, 2026) must choose between this childcare reduction or an increased tax-exempt amount of €740 per child — they cannot combine both in the same income year.

“Voor de meeste gezinnen met een jong kind dat regelmatig naar een erkende opvang gaat, zal de belastingvermindering voor kinderopvang doorgaans de grootste fiscale besparing opleveren,” explains De Beckker. “Bij beperkte of geen opvangkosten is de verhoging van de belastingvrije som vaak de betere keuze.”

3. Deduct Alimony Payments — But at a Reduced Rate

Alimony payments made in 2025 are still deductible, but the rate has dropped. Taxpayers can now deduct 70% of alimony paid (down from 80% in previous years). Conditions include a legal obligation to pay, the recipient living at a different address, and regular payments.

This is part of a broader trend of fiscal consolidation. According to Test-Aankoop, several other tax benefits have been eliminated entirely for income year 2025, including the service vouchers (dienstencheques) tax benefit, legal assistance insurance benefit, and the home EV charging station deduction.

4. Check Your Eligibility for the Flemish Housing Bonus

The Flemish housing bonus (woonbonus) is still available — but only for mortgages concluded before January 1, 2020. The benefit varies depending on when the loan was signed:

• Loans before 2015: Up to €2,280/year per taxpayer at your marginal tax rate, with an additional €760/year during the first 10 years.
• Loans between 2015 and 2019: Up to €1,520/year per taxpayer at a 40% reduction, also with the €760 first-decade bonus.

De Beckker acknowledges the phase-out can feel unfair to newer homeowners, but notes the trade-off: “De Vlaamse overheid heeft de voorbije jaren de registratierechten voor de aankoop van een enige eigen woning aanzienlijk verlaagd.”

5. Recover Withholding Tax on Dividends

Investors should not overlook dividend withholding tax recovery. For income year 2025, up to €249.90 in withholding tax can be recovered, corresponding to €833 in dividends from Belgian listed companies. This must be declared under codes 1437 and 2437 on the tax form.

Looking Ahead: Additional Opportunities

While the deadline looms, taxpayers should also keep future savings in mind. Charitable donations (from €40 minimum) now offer a 30% reduction (down from 45%), pension savings remain deductible, and flexi-jobs allow up to approximately €18,000/year in tax-free earnings for non-retired workers. The FOD Financiën also offers a “bonificatie” — a tax discount for making advance payments.

The Bottom Line

With the extended deadline of July 19, 2026, Belgian taxpayers still have a narrow window to optimize their returns. The key takeaway from experts is clear: never accept a pre-filled declaration without review. As the VRT NWS article emphasizes, a few minutes of careful checking could translate into hundreds of euros in savings.

For those with complex incomes — self-employed earnings or foreign professional income — the deadline extends to October 16, 2026, providing additional time to file through Tax-on-web.