Kosten koper (k.k.): the real cost of buying (2026)
"Kosten koper" (k.k.) means the buyer pays the purchase costs on top of the asking price — typically 4–6% in total: 2% transfer tax (0% for starters), notary fees for the transfer and mortgage deeds, a valuation (taxatie), mortgage advice, and optionally a buying agent (~1%). Financing costs are tax-deductible in year one; the transfer tax and agent fee are not.
What's included
Transfer tax (overdrachtsbelasting), notary — transfer deed, notary — mortgage deed, valuation, mortgage advice + bank guarantee, and an optional buying agent. A structural survey is extra and only deductible if the lender required it.
Deductible vs not
Financing costs — the mortgage deed, valuation, advice and NHG premium — are deductible in full in year one. Purchase costs — transfer tax, transfer deed and the buying agent — are never deductible. Our calculator applies this split automatically.