Partner

Previously, he worked in the tax advisory practice of a Big Four firm for more than 12.5 years. Koos received his PhD on the integration of the Anglo-American trust into Dutch personal and corporate tax law from Leiden University in 2011. He specializes in Dutch personal and corporate income tax and also counts payroll tax, transfer tax and gift and inheritance tax among his areas of expertise. Clients he works with range from private equity and real estate investors, to high net worth individuals, Dutch General Benefit Organizations (in Dutch: ANBIs) and (multi)national corporations.

He is also an annotator for the case law journals BNB and NTFR, an editor of Fiscaal Weekblad FED and, among other things, a regular contributor to the Weekblad voor fiscaal recht (WFR) and the Nederlandse Documentatie Fiscaal Recht (NDFR). He was a deputy judge at the District Court (Rechtbank) Noord-Holland (then: Rechtbank Haarlem) for many years and later a deputy judge at the Court of Appeal (Gerechtshof) Arnhem-Leeuwarden. Koos regularly gives lectures and teaches courses. Koos is also a board member of the Tax & Customs Museum (Belasting & Douane Museum) in Rotterdam.