Willem Otterspeer


Obtained degree in accountancy and is a fellow member of the Dutch Institute of Chartered Accountants. Also obtained a degree in civil law at the Rotterdam Erasmus University and specialised in fiscal law.

Work experience

Part-time position in the research department of the Dutch Institute of Chartered Accountants (NIVRA). Tax Auditor and Tax Commissioner with the Ministry of Finance. Tax partner with Deloitte & Touche in The Netherlands specialised in international tax law. At present partner with Otterspeer, Haasnoot & Partners, a Rotterdam based niche firm of specialised tax lawyers.

Willem Otterspeer specialises in (re)structuring of (international) groups, (de-)mergers, acquisitions, transferpricing, assistance of multinationals with tax audits conducted by the Dutch tax authorities, employee benefit schemes (including stock options) and Dutch APA/ATR practice (the former ruling practice).


Fellow Member of the Dutch Organisation of Tax Lawyers (NOB) and the International Fiscal Association (IFA).


Dutch, English, French and German

Direct dial: 
+31 10 436 50 44
Email address: