Understand · Payroll glossary
What is the marital quotient?
Updated on
The marital quotient assigns part of one spouse’s income to the other when the latter has little or no professional income: the couple pays less tax. In 2026: €11,780 (marital quotient ceiling, 2026 income (spouses under 66)). In Dutch: huwelijksquotiënt.
Definition of the marital quotient
It concerns married couples or legal cohabitants taxed jointly. Up to 30% of the professional income of the higher-earning spouse is assigned to the other, minus the latter’s own income, subject to a ceiling.
The reform passed in 2026 reduces it every year: the ceiling falls from €11,780 for 2026 income to €6,730 for 2029 income. Withholding tax (bedrijfsvoorheffing / précompte professionnel) takes it into account when your spouse has no income.
The key figure in 2026
Source: Act of 15 July 2026 reforming personal income tax (Belgian Official Gazette of 29 July 2026), Belgian Official Gazette. See also: Réforme de l’impôt des personnes physiques (4 August 2026), Wolters Kluwer (secondary source). Next: €10,110 for 2027 income (law passed).
Worked example
A white-collar worker on €4,000 gross, married to someone with no income: their withholding tax falls from €826.70 (single) to €407.18, and their net pay rises from €2,614.26 to €3,035.67. Over the year, €10,697 of their income is assigned to their spouse.
In Dutch: huwelijksquotiënt
On a Dutch-language tax return, tax assessment notice (aanslagbiljet) or letter from the tax authorities, the marital quotient is called ‘huwelijksquotiënt’; on French-language ones, ‘quotient conjugal’.
Dutch term taken from: Wolters Kluwer (Jef Wellens) (secondary source).
Not to be confused with…
- De facto cohabitation: de facto cohabitants (unmarried partners who are not legal cohabitants) are taxed separately: they have no marital quotient.
- Tax-free amount: the part of your annual income on which you pay no tax: €11,550 for 2026 income.
Calculate it for your situation
What marriage or legal cohabitation changes in your net pay and in household tax.
Related terms
- Personal income tax (PIT)Tax and tax return · in Dutch: personenbelasting
- Tax-free amountTax and tax return · in Dutch: belastingvrije som
Sources
Parameters in force on 1 October 2026. Each parameter links to its source, the official one where it exists; a secondary source is flagged as such.
- Loi du 15 juillet 2026 portant réforme de l’impôt des personnes physiques, published on 29 July 2026, Belgian Official Gazette. Cross-checked with: Attentia and Wolters Kluwer.
- Réforme de l’impôt des personnes physiques (4 August 2026), Wolters Kluwer (secondary source).
- Calcul du précompte professionnel : annexe III de l’AR/CIR 92 et formule-clé 2026, FPS Finance.
- Overzicht van de belangrijkste fiscale grensbedragen in de personenbelasting (aanslagjaar 2026), Wolters Kluwer (Jef Wellens) (secondary source).