We have years of experiences and feel comfortable with national as well as international matters. For you we develop customized solutions based on numerous business cases and templates. You select the scale our service but profit from our full know-how. Do you have foreign business partners? We are also for this the right contact thanks to the international network of INPACT.

We strive for a long-term partnership with our clients, employees and authorities. The WIESER Treuhand Gruppe sees itself as a fair partner. We appreciate frankness and commitment.

Stefan Wieser
Stefan WieserOwner and CEO

Stefan Wieser has founded the group in 2001. Before that he worked amongst other positions at PricewaterhouseCoopers in Switzerland and abroad. Stefan Wieser has a degree as business economist HWV, a diploma as swiss certified public accountant, is certified VAT specialist and licensed audit expert. Stefan Wieser himself has extensive experience in any kind of finance, tax and administration. He is board member, manager and director of about two dozen companies and an experienced entrepreneur. Stefan Wieser personally takes care of demanding annual financial statement, every audit- and challenging consulting mandate. In his leisure Stefan Wieser is a passionate sailor, who races against other boats, organizes blue water cruises and has crossed the Atlantic several times. With his motorcycle he explores the countries along the silk road. Further, Stefan Wieser is a member of the old boys network “Die Nothensteiner“.

Boba Kaiser
Boba KaiserSenior Manager

Boba Kaiser is a valuable pillar of our team since 2004 and became manager in 2010. She did her apprenticeship at a fidcuciary company and has ever since worked in this field. Boba Kaiser is specialized in annual financial statements, payroll accounting, human resource management and tax returns for individuals and corporations. Boba Kaiser is married and mother of a son and a daughter. In her leisure she likes to read and swim.

Renate Kohler
Renate KohlerManager

Renate Kohler has joined our team in 2014 and became manager 2018. After her apprenticeship in a fiduciary company she gained experience in an SME fiduciary company and in the two Big Four companies Ernst & Young AG and KPMG AG. Renate Kohler deals with accounting till the preparation of annual financial statements as well as human resources management. Further, she is specialized in value-added tax as well as taxes for individual persons and corporations. As she is an English native speaker, she provides support to a lot of your foreign-language clients. At the present time she is training while working for her Federal Diploma of Higher education (Certified Fiduciary). She compensates her work with sports and likes to travel.

Marina Ramsauer
Marina RamsauerJunior Manager

Marina Ramsauer joined our team in 2017. After her apprenticeship in the public administration, she worked in several accountancy departments for private companies. She is a junior accountant and has an extensive know-how in accounting, tax and social security.  At the present time she is training while working for her Federal Diploma of Higher Education (Chartered Specialist in Accounting and Financial Management). She loves sports and enjoys outdoor activities, especially in the mountains.

Fidan Mustafa
Fidan MustafaApprentice

Fidan Mustafa joined our team in August, 2018 and is doing an apprenticeship of three years as commercial employee. He is responsible for the accounting of our group, IT support and tax declarations of physical persons. His hobby is  playing soccer in a local club.

Social commitment

We are engaged and characterized by persistence. We support since our foundation the aid organisation Coup de Pouce Vietnam. We know the volunteers of the association in Hanoi partly personally.


At the moment we have no vacancies.

At the moment we have no trainees.