Mark Tonkovich 2818

Mark Tonkovich

Baker & McKenzie LLP


Mark Tonkovich is a partner practicing exclusively in the tax controversy field. He sits on Baker McKenzie's North America Tax Controversy Steering Committee and leads the Firm's Pro Bono Practice in Toronto. The Canadian Federal Court of Appeal commented on his work as follows in a 2013 judicial review application: "In exemplary fashion, Mr. Tonkovich untangled a confusing body of evidence and argument, discerned the most important legal issues, and effectively presented submissions that were of significant assistance to the Court in the efficient resolution of this case."

Prior to joining the Firm, Mr. Tonkovich was a government tax litigator with the Department of Justice and a judicial clerk at the Federal Court of Appeal. He held a Lord Beaverbrook Scholarship in Law and received several academic awards including those in corporate law & taxation, administrative law, and professional conduct (ethics). He has published dozens of articles on Canadian tax matters, including works in the peer-reviewed Canadian Tax Journal and the National Journal of Constitutional Law. He is a frequent contributor to several legal publications and professional organizations, has appeared as an invited witness before the House of Commons Standing Committee on Finance, and he regularly speaks at events for tax professionals.

Practice Focus

Mr. Tonkovich helps clients resolve all manner of tax and public law disputes with the Canada Revenue Agency and other Canadian tax authorities. He works on all aspects of the dispute resolution process, including the analysis of tax assessment and litigation risks, disclosure and negotiation with government agencies, audit management and defence, administrative appeals, and litigation in federal and provincial courts. He has provided dedicated, effective, and practical representation to clients in the Tax Court of Canada, the Federal Court, the Federal Court of Appeal, the Ontario Superior Court of Justice, the Court of Appeal for Ontario, the Court of Appeal of Alberta, and in resisting leave to appeal to the Supreme Court of Canada.

Representative Legal Matters

  • Trial-level tax disputes concerning the general anti-avoidance rule (GAAR), the taxation of foreign affiliates, the scientific research and experimental development (SR&ED) tax incentive program, and the tax consequences of employee fraud.
  • Appellate-level cases concerning the GAAR, employer-provided taxable benefits, and the implementation of the provincial reassessment waiver regime.
  • Appellate-level judicial intervention on behalf of the Canadian Bar Association concerning fundamental precepts of solicitor-client privilege.
  • Applications for judicial review concerning the CRA's refusal to provide relief from double taxation under the Canada-US Tax Treaty, its failure to issue timely assessments of federal income tax, and the intersection of employment insurance and bankruptcy law.
  • Provincial rectification proceedings to correct substantial transactional errors in a cross-border hybrid refinancing plan.
  • Administrative appeals relating to foreign affiliates, and to the scope and validity of provincial income tax assessments.
  • Submissions to the CRA's Transfer Pricing Review Committee defending against the application of transfer pricing penalties.
  • Advised on potential administrative and judicial appeals pertaining to contractual break fees and the taxation of mining profits.
  • Guided clients through a large number and variety of tax audits, including in the context of reviews by the CRA's Aggressive Tax Planning Section, the foreign affiliate regime, employee/independent contractor classification, and the SR&ED program.
  • Navigated clients through the CRA's Voluntary Disclosure Program for a complex web of cross-border transactions involving over three dozen legal entities.

Professional Associations and Memberships

  • International Tax Review - Tax Controversy Leader
  • Ontario Bar Association Taxation Law Section - Past Chair (Previously: Chair; Vice-Chair, Secretary, Newsletter Editor)
  • Tax Litigation (a Federated Press Journal) - Editorial Board
  • Canadian Tax Foundation - Member (Previously: Toronto YP Steering Committee)
  • The Advocates' Society - Member
  • Canadian Bar Association - Member
  • International Fiscal Association - Member
  • Halton County Law Association - Member
  • Ukrainian Canadian Bar Association - Member


  • Ontario~Canada (2009)


  • Osgoode Hall Law School (LLM Tax) (2014)
  • University of New Brunswick (LLB Distinction) (2008)
  • University of Guelph (BA) (2005)


  • Croatian
  • English
  • Ukrainian