Profile
Work Department
Position
Katerina is a senior associate with the Firm since 2014
Career
Katerina's practice focuses on tax, administrative and company law. Katerina advises domestic and multinational corporations, institutions, and individuals during the conduct of tax audits and represents them in all phases of tax disputes, both in judicial and out-of-court level. Katerina has also experience in a variety of direct and indirect taxation matters and she advises domestic and international clients on taxation and tax planning implications arising in the course of their business.
Recent hilights include:
- Advised major domestic entity in relation to the tax treatment of its transactions with cross-border entities established in countries having a preferential tax regime.
- Advised Greek financial institution in relation to the refund (adjustment) of input VAT paid for the purposes of real estate construction.
- Advised multinational client in relation to the imposition of stamp duties on intra-group cash pooling transactions.
- Advised Greek insurance company in relation to the tax treatment of contributions paid by the company and its employees in favour of a Pension Fund set up by the company.
- Advised international organization with regard to the fiscal nature of the special solidarity contribution.
- Advised Greek corporation with regard to its dispute with the Tax Authority in connection with the deductibility of a tax loss of past fiscal years.
- Advising and representing international group in relation to the alleged personal liability of two executives of the group (who have acted as directors of a Greek company acquired by the group) for the company’s tax debts.
Prior to joining the firm, Katerina has worked in the legal department of Nordea Investments Funds S.A, located in Luxembourg.
Languages
Memberships
Education
Chartered Institute of Taxation – Advance Diploma in International Taxation.
Athens University of Economics and Business – Tax Law for Lawyers, 2016.
Democritus University of Thrace – LLM in Commercial law with Specialisation in Competition law, 2015.
Freie University of Berlin – Master in Business Law, 2013.
Democritus University of Thrace School of Law – Law Degree (Ptychion), 2010.
Content supplied by Fortsakis, Diakopoulos, Mylonogiannis & Associates Law Firm
Testimonials
Collated independently by Legal 500 research team.
‘Petros Pantazopoulos has deep knowledge of tax law and administrative law.'
‘I have collaborated with Petros Pantazopoulos and Katerina Sideromenou. I would say that their main characteristics consist of their broad knowledge of their field, their capacity to understand and handle the issues in a holistic way and their willingness to listen carefully to their clients.'
‘What makes this practice unique is the combination of professionalism with a genuinely client-focused approach. The team demonstrates deep legal expertise while maintaining excellent communication, always ensuring that complex matters are explained clearly and that clients feel supported throughout the process. Compared to other firms, this practice stands out for its responsiveness and consistency in delivering high-quality advice.’
‘The individuals I have worked with stand out for their attentiveness, reliability, and commitment to achieving the best outcome for their clients. They differentiate themselves through their ability to combine strong technical knowledge with empathy and a practical approach, which makes collaboration both effective and pleasant. What I value most is their availability, clear communication, and proactive engagement.'
‘Katerina Sideromenou is a highly experienced professional, with an exceptional work ethic. She is a reliable professional who sees her client's needs as a top priority.’
‘What makes this legal team unique is their profound knowledge of the tax practice area, their client friendly approach as well as their prompt responsiveness and professionalism.'
‘The firm stands out for being highly responsive and efficient. While their tax expertise is excellent, I particularly value their broader business law knowledge, which allows them to provide well-rounded and practical advice. Compared to other firms, their combination of speed, breadth, and client focus is a real strength.’
‘They are approachable, responsive, and always willing to go the extra mile to provide clear, timely, and practical advice. Their ability to understand our business context and translate complex legal matters into actionable solutions is highly valued.’
Key clients
- Nova Telecommunications & Media Single Member S.A. Mars Hellas Single Member S.A. Lignitorycheia Achladas A.E. Museum of Cycladic Art Freeport Navigation Inc Piraeus Port Plaza 2 Astir Pallas Alpha Leasing Alpha Leasing Viva Wallet Vodafone Pharmaserve - Lilly SACL Nostira Golden Eggs Group Archeiothiki S.A. Tora Wallet Elvo S.A.