Tomasz Siennicki Associate Partner with Kolibski, Nikończyk, Dec & Partnerzy. He has many years of professional experience, which was first gained while working for tax authorities, and then – since 2005 – while exercising a regulated profession of a tax advisor. During his professional career, Siennicki advised clients from the majority of industries, including specifically fuel, building and advertising, rendering current tax advisory services and representing them in disputes with tax authorities.

Tomasz Siennicki is an author of numerous articles on taxes published in specialist press as well as co-author of commentaries on personal income tax and corporate income tax acknowledged by experts in that field, published by C.H. Beck on an annual basis.

Furthermore, Tomasz Siennicki gives lectures at the Postgraduate School of Tax Law, Lazarski University in Warsaw.