Wet Hillen: relief for a small or paid-off mortgage (2026)
The Wet Hillen (aftrek wegens geen of geringe eigenwoningschuld) protects owners whose mortgage is small or fully repaid. Normally the eigenwoningforfait adds to your taxable income; if your deductible interest is less than the forfait, this rule gives an extra deduction so you aren't taxed on the surplus. It's being phased out at 3⅓% a year — in 2026 it covers about 71.9% of the surplus, and it disappears around 2048.
When it applies
If you've paid down or fully repaid your mortgage, your deductible interest can fall below the eigenwoningforfait. Without Wet Hillen you'd be taxed on the difference — effectively taxed for having little debt. The deduction cancels most of that surplus so ownership stays attractive once the mortgage shrinks.
The phase-out
Since 2019 the relief drops 3⅓ percentage points each year. In 2026 it offsets roughly 71.9% of the forfait surplus; by around 2048 it reaches zero, after which owners with no mortgage will be taxed on the full forfait. The calculator applies the 2026 Hillen percentage automatically.