Matthias Beltzig has a training as Steuerfachangestellter (tax assistant) with subsequent studies of economics in Wiesbaden. He worked in the field of auditing at one of the world's largest auditing companies, followed by a position as managing director of a tax consulting firm.

As tax advisor, Matthias Beltzig advises in particular corporations with business relations to affiliated companies abroad.

His main areas of consultancy include advising on issues of international tax law, the determination and documentation of transfer prices, the preparation of annual financial statements and tax returns for German subgroups and the preparation of permanent establishment profit accruals. Another focus of his work is tax advice in the area of group restructuring as well as in tax audits of group companies.