About us

In August 2003, Allard Lubbers was appointed as Professor of Tax Law at Leiden University. He specializes in the determination of ‘profits’ for (corporate) income tax purposes and in procedural tax law. He wrote a number of books (in Dutch), including 'Reading and analyzing decisions of the Supreme Court' and 'Sound business practice'. He has published widely in the areas of his specialization. To mark the 100th anniversary of the Tax Chamber of the Supreme Court in 2016, Allard was awarded the prestigious title ‘Watcher of the Dutch Supreme Court’. Allard was a deputy judge the Courts of Appeal of Amsterdam and ‘s-Hertogenbosch between 2002 and 2017. Together with Koos Boer, Allard Lubbers is the founder of Lubbers & Boer B.V.

Koos Boer has been Professor of Tax Law at Leiden University since 2013. He was the Head of the Tax Law Department until February 2020. Prior to founding Lubbers & Boer BV with Allard Lubbers in March 2013, Koos practiced tax law at one of the Big Four tax law firms in the Netherlands. Koos is specialized in Personal and Corporate Income Tax Law. He wrote his dissertation (2011) on the tax law aspects of Anglo-American trusts. Koos publishes regularly in several legal journals (BNB, WFR and NTFR) and is an editor of Fiscaal Weekblad FED – a weekly case law journal. For years he was a deputy judge in the District Court of Haarlem and in the Court of Appeal of Arnhem-Leeuwarden. Koos gives lectures and teaches courses on various topics.

Sjoerd Douma is Professor of International & EU Procedural Tax Law at the University of Amsterdam. Prior to his appointment in October 2017, he was a professor at Leiden University. At the IFA Congress in Rio de Janeiro (2017), Sjoerd was appointed as a member of the Permanent Scientific Committee of the International Fiscal Association. Sjoerd has specialized in corporate income taxation, tax treaties, European tax law (including Fiscal State Aid) and procedural law. Sjoerd is the lead instructor in the massive open online course ‘Rethinking International Tax Law’ which has attracted more than 30,000 participants from all over the world. In 2017, Sjoerd received Coursera's Learners First Outstanding Educator Award, out of over 2,000 courses on Coursera. This award honours the instructor who best exemplifies the “Learners First” principle, as demonstrated by a combination of course ratings and course completions. Sjoerd has been a Deputy Judge in the Court of Appeals of Arnhem-Leeuwarden, a Deputy Judge in the District Court of Haarlem and Visiting Professor at Université Panthéon-Assas (Paris, France). He is a permanent contributor to leading Dutch and international tax journals. He has authored and co-authored numerous publications and reports on national, international and European tax law. In 2012, Sjoerd’s PhD thesis ‘Optimization of Tax Sovereignty and Free Movement’ won the prestigious bi-annual Dissertation Prize of the Dutch Association for Tax Research. Prior to joining Lubbers, Boer & Douma in March 2017, Sjoerd has practiced tax law at one of the ‘big four’ tax advisory firms for more than 12,5 years. Sjoerd has represented clients before the tax authorities, the Dutch tax courts (including the Dutch Supreme Court), the European Commission and the Court of Justice of the European Union. Sjoerd has acted multiple times as an expert witness in international arbitration and court proceedings. He has also acted as arbitrator. Before joining private practice, Sjoerd was a legal clerk at the Dutch Supreme Court, where he drafted judgments as well as opinions of the Advocate-General.

Alexia Kardachaki has been working for Lubbers, Boer & Douma since April 2020. Alexia has specialized in international and EU tax law. Prior to joining Lubbers, Boer & Douma, Alexia gained practical experience working for 7 years with two of the Big Four firms as tax advisor of large Dutch-based multinationals. She also focused on EU State aid law, tax transparency and dispute resolution. Alexia holds an LL.M. in international tax law (Vienna University of Economics and Business), an LL.M. in Dutch tax law (Vrije Universiteit Amsterdam), and a postgraduate diploma in Greek tax law (Athens University of Economics and Business). In 2021, Alexia completed the executive programme in transfer pricing (University of Lausanne). She also has a background in tax research, having acted as researcher for the International Fiscal Association, and is actively involved in the academic world.

Mart van Hulten has been working as a tax lawyer at Lubbers, Boer & Douma since July 2020. He is also assistant professor in European and international taxation and in Dutch corporate taxation at the Fiscal Institute of Tilburg University. Prior to working at Lubbers, Boer & Douma, Mart worked at one of the Big Four’s international and European corporate tax advisory practice for 12 years. Mart is annotator at NLFiscaal, a weekly tax journal. Other contributions of Mart to academic literature can for instance be found in the Journal of International Taxation, EC Tax Review, and Intertax. In December 2019, Mart successfully defended his PhD thesis at Tilburg University, titled ‘Aiming for Well-Being through Taxation: A Framework of Caution and Restraint for States’.

Claire Maree has been working for Lubbers, Boer & Douma since November 2020. She has specialized in (the international aspects of) corporate income tax, personal income tax and dividend withholding tax. Prior to joining Lubbers, Boer & Douma, Claire gained practical experience working for one of the large tax advisory firms in the Netherlands. Claire holds an LL.M. in Dutch tax law from Leiden University (cum laude) and bachelor’s degrees in tax law and jurisprudence. Claire has completed an internship at the Dutch Supreme Court, where she wrote draft Opinions for one of the Advocates General.

Rocco IJsselmuiden has been working at Lubbers, Boer & Douma since April 2021. Prior to joining Lubbers, Boer & Douma, he worked for three and a half years as a lawyer and tax adviser within the integrated tax practice of a global law firm in Amsterdam, where he gained experience across the full spectrum of (international) tax law. He was also a member of the Technical Committee of the Young Association of Tax Advisers. Rocco graduated in tax and civil law from Vrije Universiteit (VU) Amsterdam and Leiden University in 2017. Rocco completed an internship at the Dutch Supreme Court and was a student assistant at the tax department of VU Amsterdam. 

Luc Mengelers has been working at Lubbers, Boer & Douma since September 2021. Luc graduated in Dutch tax law from Tilburg University in 2021. He wrote his Master's thesis about the compatibility of the Dutch dividend witholding tax with European law. Luc won the thesis award for his Bachelor's thesis about the liquidation loss scheme in the Dutch corporate income tax. During his study, Luc worked at the tax section of the Dutch court of appeal in 's-Hertogenbosch. Furthermore, he has completed an internship at the Dutch tax authorities in Eindhoven on the departments Private Persons and Large Enterprises. Luc is a member of the Association for Tax Sciences.

Rupal Maheshwari has been working for Lubbers, Boer & Douma since June 2022. Rupal has specialized in international tax law and holds an Advanced LL.M. in international tax law from the University of Amsterdam (cum laude). She wrote her master’s thesis on ‘Pillar One & Value Creation’ and won the IBFD Award for the Best Thesis 2022. She is also a Chartered Accountant from India along with a bachelor’s degree in commerce from Shri Ram College of Commerce (University of Delhi).  Prior to joining Lubbers, Boer & Douma, Rupal had professional experience working for nine years in India with one of the Big Four firms and a boutique tax firm in the domain of corporate and international taxation. During her study, she also did internship in transfer pricing domain at a Dutch law firm.