Eigenwoningforfait: the home-ownership levy (2026)
The eigenwoningforfait is a notional "income" the tax office adds to your Box 1 income simply for owning the home you live in. In 2026 it is 0.35% of the WOZ value for homes up to €1,350,000 (above that, €4,725 plus 2.35% on the excess). On a €400,000 WOZ that's €1,400 added to your taxable income — which then offsets part of your mortgage interest deduction.
How it's calculated
Take your WOZ value and multiply by 0.35% (the 2026 rate up to €1,350,000). That amount is added to your taxable income in Box 1. It isn't a bill you pay directly — it reduces the net benefit of your mortgage interest relief, because relief is calculated on your interest minus the forfait.
For most owners with a normal mortgage, the interest is far larger than the forfait, so you still get a net deduction. The calculator applies the forfait month by month against your interest before working out the relief.
Why it exists
The forfait is the flip side of mortgage interest relief: the state treats your home as producing a small taxable benefit, and in return lets you deduct the interest. If your mortgage is small or paid off, the Wet Hillen deduction steps in so you're not taxed on the forfait surplus — see that guide.