About Onestoptax

OnestopTax BV offers integrated tax services specifically geared towards expatriates and their employers. By specifically focussing on expatriates we have acquired expert knowledge through more than 25 years of experience. With emphasis on personal service, expertise, speed and at competitive fees.

We are a growing expatriate tax advisory and compliance firm that is dedicated to advising employers and their employees in respect to all matters relating to cross border employment. We are specialised in cross border employment situations and compensation structures with a focus on compliance, immigration and implementation.

One single point of contact

OnestopTax BV means one point of contact for your specific service, whether you are looking for assistance with your Dutch Tax Return, with the application of your 30% ruling, your visa application or are in need of advice. We offer professional, personal service and a short turn-around preparation time. This is our added value!


OnestopTax BV can advice and provide practical solutions meeting the specific objectives of companies with internationally mobile employees. Our goal is to also assist employers with the correct and timely implementation of our recommendations in their administration so our work does not stop!


With more than 25 years experience in advising Dutch and foreign-based companies and their expatriate employees we can provide expatriate tax solutions and make sure your company is in compliance with all applicable employment, tax, immigration and social security laws. Our international network ensures that we have ample contacts with other providers to cover all services related to expatriate employees.

Company Strategy

OnestopTax BV is dedicated to providing you with professional assistance tailored to your unique tax position. In addition, onestopTax BV offers a personal level of service, one point of contact, quick turnaround preparation time whilst maintaining very competitive fees.

This is achieved by focussing on expatriate services only. In addition, onestopTax BV's business model is based on sustainability rather than growth and expansion. By carefully balancing the volume of clients against the level required to sustain the business, you, as our client, can count on more attention and better service making the entire process a lot more enjoyable.

  • Over 25 years of experience in Expatriate Taxation
  • Expert knowledge of Dutch wage and income tax
  • Competitive fees
  • Personal attention
  • Expert knowledge of 30% ruling
  • Added value through personal approach to service
  • One contact person
  • High service level

Meet the team

Allard Roeper
Allard gained more than 12 years of experience as a taxlawyer with the “big four” consultancy firms Deloitte and PwC. In 2008 Allard also started focussing more on immigration law as added value to his expatriate tax consultancy services. In September 2009 Allard founded onestopTaxConsult providing consultancy tax services to expatriates and their employers. In 2012 Allard decided to incorporate tax consultancy and tax preparation into one company under the name onestopTax BV. In his free time Allard enjoys kitesurfing preferably in Caribbean waters.

Tel: +31 20 8200 657
Email: allard.roeper@onestoptax.nl

Elaisa Poerschke
Elaisa started working as an Expatriate Tax Consultant at onestopTax BV as of September 2010 focussing on tax planning and consultancy to employees and employers with respect to international mobility. Elaisa completed her Master´s degree in Fiscal Law at the VU Amsterdam in 2012. In 2020 she became senior tax manager in expatriate taxation at onestopTax BV. Elaisa has gained the specific expertise and knowledge to fully assist and advise clients on international taxation and has successfully provided interim services and international wage tax scans with clients on site. In her free time Elaisa designs jewelry and in 2017 she started her own webshop PurpleDrawers.com.

Tel: +31 20 8200 657
Email: elaisa.poerschke@onestoptax.nl

Oscar Halacre
Oscar started his career at Ernst & Young in 2000 as a US tax preparer. In 2004 Oscar joined TaXpat BV and started specializing in the preparation of Dutch and US income tax returns. As of June 2010 Oscar started working independently providing Dutch tax preparation services together with onestopTax BV.

Tel: +31 20 8200 657
Email: oscar.halacre@onetoptax.nl

Sibel Serin
Sibel worked for more than 5 years within the big- four advisory businesses of Deloitte and Ernst & Young. As per 2009, she continued her career as an in-house company Tax Lawyer at Hewlett Packard where she was responsible for domestic and international Employment Tax matters within the Benelux region. In 2015 Sibel also started to work independently as a Tax Advisor providing Expat / International Payroll Services. In her spare time Sibel enjoys a long walk on the beach followed by a good cup of coffee in her husband’ s espresso bar whilst reading a good book.

Tel: +31 20 8200 657
Email: sibel.serin@onestoptax.nl

Tijn Jansen
Tijn started working as a part-time Expatriate Tax Consultant per February 2022. He finished his bachelor degree in both Fiscal Law (UvA) and Fiscal Economics in July 2021. In 2024 Tijn intends to also finish his Master in Dutch tax Law (UvA). During his study, he wants to enlarge his fields of interests and one day he would like to become a lawyer. In his youth Tijn was a professional soccer player and he still enjoys playing and watching soccer. Tijn enjoys cooking for friends and family, and having drinks with friends.

Tel:  +31 20 8200 657
Email: consult@onestoptax.nl

International Network

OnestopTax is member of the international network of Taxplanet. TaxPlanet is a worldwide network of independent legal and accounting professionals specializing in tax, both at national and international levels.

The pool of experts consists of tax professionals from independent legal and accounting firms located around the world. Currently this network consists of some of the best tax advisors from more than 35 countries.