Louis Tassé

Louis Tassé

Partner, Tax

Key Contact: Tax Controversy and Litigation

Contact Information


tel: 514.904.8170



Bar Admission

Québec, 1990


  • Université de Montréal, LL.B.


French, English

Louis is the Head of Osler’s tax litigation practice in Montréal. His practice focuses primarily on tax litigation, both in income and sales tax cases. He has deep and varied experience litigating tax cases for the Crown and is well-versed on controversies affecting corporate taxpayers and understands the Crown’s perspective in litigating tax cases.

Prior to joining Osler, Louis practiced in one of the largest professional services and accounting firms in the world, representing clients in disputes with the Canada Revenue Agency and the Québec Ministry of Revenue. Most notably, Louis successfully represented J.D. Irving Limited in the Court of Quebec and the Quebec Court of Appeal (loss consolidation income tax), Kruger (income tax), Salaison Lévesque Inc. (sales taxes), ADP Canada Co. (large corporations tax), Ikea Ltd. (sales taxes), and Joseph Ribkoff Inc. (sales taxes). His track record of reported cases involves both income and sales taxes in the Québec courts, the Federal Court of Appeal and the Tax Court of Canada, and his early career experience with Justice Canada and Revenue Canada. Louis also has extensive experience in voluntary disclosures both for income tax and sales tax matters, with the Canada Revenue Agency and Revenu Québec. Louis is a prolific writer and has been quoted on three different occasions by the Tax Court of Canada and the Québec Court.

  • J.D. Irving Limited

    J.D. Irving Limited in its successful appeal of Revenu Québec’s reassessments

    • Agence du revenu du Québec v. J.D. Irving Limited,  2022 QCCA 241
    • Distributions Maroline inc. v. Agence du revenu du Québec, 2021 QCCQ 2560 
    • Kruger v. The Queen, 2016 FCA 186
    • SNF L.P. v. The Queen, 2016 TCC 12
    • Kruger v. The Queen, 2015 TCC 119
    • Salaison Lévesque Inc. v. The Queen, 2014 FCA 296 and 2014 TCC 36
    • Reluxicorp Inc. c. La Reine, 2011 TCC 336
    • Sommerer v. The Queen, 2011 TCC 212
    • ADP Canada Co. v. The Queen, 2009 FCA 117
    • Les Placements G. Douglas inc. et al. c. Les Placements Lac St-Louis inc. et l’Agence du revenu du Canada et l’Agence du revenu du Québec, mis en cause, no 500-17-040750-088
    • Joseph Ribkoff Inc. c. La Reine, 2003 TCC 397
    • S.P. Holdings Canada c. Ikea Ltd., 2002 ETC 2835 (QCCA)
  • Find More

  • The Canadian Legal Lexpert Directory: Recognized in Litigation – Corporate Tax
  • Best Lawyers in Canada: Recognized in Tax Law

  • Member, Association de planification fiscale et financière, Tax Administration Conference Committee
  • Member, Canadian Tax Foundation
  • Member, Association de planification fiscale et financière
  • Former Governor, Canadian Tax Foundation

  • "Federal Court of Appeal decision in Cameco", Tax Executives Institute, September 2020.
  • "Preventing, Navigating and Resolving Tax Disputes", Canadian Tax Foundation, May 2018.
  • "Commodity Tax – Case Law Update", Tax Executives Institute, May 2017.
  • "Preventing, Navigating and Resolving Tax Disputes: A Dialogue with the Tax Court of Canada", Canadian Tax Foundation, April 2017.
  • "Jurisprudence fiscale et administrative", Association de planification fiscale et financière, 2016.
  • "Les agences de placement", Association de planification fiscale et financière, March 2015.
  • “Invoices of Accommodation: The Salaison Lévesque Inc. Case”, Tax Planning International Indirect Taxes, June 2015.
  • "Pot-pourri en administration fiscale", Association de planification fiscale et financière, 2015.
  • "Panel sur les développements récents en administration fiscale", Association de planification fiscale et financière, 2014.
  • “Placement Agencies and Subcontracting – Entitlement to ITC and ITR”, APFF 21st Commodity Tax Symposium, 2014.
  • “Lessons from the Great White North and Down Under – Thoughts on Recent Transfer Pricing Decisions”, Tax Notes International, 2009.