Jaak Siim

Partner | Attorney at Law

Main practice areas

    • Administrative procedure
    • Tax and Customs
    • Litigation in administrative and civil cases
    • Defence and representation in criminal and misdemeanour matters


  • 2004 University of Tartu, Bachelor of Arts Degree in Law (equivalent to Master’s Degree)
  • 1998 Tallinn School of Economics, law specialty

Work experience

  • 2019-… Cuesta Law Office, partner
  • 2008-2019 LEADELL Pilv Law Office, associate, senior associate and partner (since 2012)
  • 2004-2008 Tax and Customs Board, Head of Division of Special Proceedings of the Legal Department, Chief Lawyer of the Division of Customs Law of the Legal Department
  • 1999-2003 Customs Board, Senior Specialist and Chief Specialist of the Legal Aid Division of the Legal Department, Specialist of the Legal Division of the Customs Enforcement Division

Professional activities

  • Jaak Siim has been a member of the Estonian Bar Association since 2009 and has been a senior associate since 2011.
  • In its 2022, 2023 and 2024 reviews, the prestigious international publication Chambers and Partners acknowledged Jaak Siim’s work in tax law, noting his work in representing clients in tax audits and responding to inquiries during tax authority investigations.
  • The largest international publication compiling reviews of the legal market The Legal 500: Europe, Middle East & Africa has recognized Jaak Siim as a leading lawyer in tax law and dispute resolution. Jaak Siim is “strong litigator” in dispute resolution: “vastly experienced and provides quick and expert answers” in tax law. He is also considered as a „superstar regarding white-collar crime cases and works day and night for the best results“. The publication has recognized Jaak Siim in its publications for the years 2012-2018 and 2023-2024.
  • The international publication Best Lawyers has recognized him from 2013 to 2018 as one of the best experts in Estonia in the areas of administrative law, tax law and criminal proceedings.
  • Jaak Siim has written numerous articles for various economic and legal publications and has been a lecturer at various seminars. Jaak Siim has been a lecturer in a field of customs law at Tallinn School of Economics