Nicolai started his career in 2005 at a Big Four company in Zurich, where he last served as a Senior Manager until 2014. During this period Nicolai was able to train and obtain the diploma of Certified Tax Expert.
From October 1, 2014, to May 2017 Nicolai held the position as Head Group Tax of a listed international technology group domiciled in the Canton of Zug.

From 2017 to 2019 Nicolai led the tax department of one of the largest auditing and consulting firms in Liechtenstein as a partner.
Most recently Nicolai started his own business as independent tax advisor which converged with Andersen in Switzerland since 2024.

With 20 years of experience in the area of corporate tax advisory and international corporate tax, Nicolai specializes in the areas of mergers & acquisitions, succession planning, international reorganizations, transfer pricing, optimization of group structures, and tax litigation. He is well acquainted with the Swiss tax authorities and has successfully led various tax audit and tax ruling negotiations with the Swiss tax authorities.