Diane Tsonos




Phone: 514.934.3436
Fax: 514.934.3408
Address: 1981 McGill College, 11th Floor
Montréal, QC H3A 0G6


Tax, Estate Planning and Administration

Diane Tsonos is a highly experienced and committed tax professional with more than 25 years of estate planning, trust and Canadian tax experience, with a particular focus on real estate taxes and the taxation of Canadian shareholders living in the U.S. She is a member of the Québec Bar and has held the title of Trust and Estate Practitioner (TEP) since 2002.

Diane is the partner in charge of the firm’s Estates Group within the Tax division. Her responsibilities include developing estate plans for owner-managers and providing strategic advice to estate liquidators and trustees to ensure the successful transfer of property to beneficiaries from a multi-disciplinary perspective. She is also actively involved in settling disputes with government revenue departments. Her Canadian tax clients operate in the manufacturing and services sectors, with a concentration in Real Estate.

Diane speaks and lectures frequently on tax-related topics for organizations such as the Society of Trust and Estate Practitioners, the Association de planification fiscale et financière and the Canadian Tax Foundation. She has been a recurring lecturer for the Canadian Tax Foundation on tax planning for the owner-managers and for McGill University on real estate taxation. Her most recent conferences have covered topics such as post-mortem planning, spousal trusts, and tax-deferred transfers. She is also regularly called upon by the media to comment on tax and business issues.

Fields of expertise

  • Estate planning and trusts
  • Settlement of estates
  • Real estate taxation
  • Strategic advisory services


  • Real estate
  • Services
  • Manufacturing

Professional and Community Involvement

  • Member of Foundation of Greater Montreal - Member of the Board of Directors, since 2016
  • Member of Canadian Bar Association since 1983, Vice President, Branch (Québec) – Wills, estates and trusts since 2012
  • Association de planification fiscale et financière (APFF) - Member of the Board of Directors since 2009, Member, since 1986
  • Society of Trust and Estate Practitioners - Member and former Executive Committee Member, Montréal Branch, since 2002
  • International Women’s Forum of Canada - Member and former treasurer, since 1996
  • Batshaw Youth and Family Centres - Former president and member of the Board of Directors, 1992 – 2002
  • Member and former governor of Canadian Tax Foundation Executive Committee, since 1986

Public Recognition

  • Quoted in an article by Matthew Elder. “Sold your home? The tax man wants to know,” Morningstar, August 2017.
  • Quoted in an article by Isabelle Massé. “Métro, boulot...bien-être!,La Presse (Affaires), p. 7, August 2012.
  • Quoted in an article by Isabelle Massé. “Bien gérer un déménagement,” La Presse (Affaires), p. 7, August 2012.
  • Quoted in an article by Allison Lampert. “Spaced out: The new workspace of fewer closed doors, less privacy and more lounging areas is reinventing the way people work - and it's no longer a trend confined to the tech industry,” The Gazette, p. C1, August 2012.
  • Speaker. “Mise à jour sur la vérification des fiducies,” lunch conference, APFF, 2012.
  • Quoted in the article entitled “Une fiducie en faveur de soi-même au lieu d'un mandat d'inaptitude,” Finance et investissement, December 2011.
  • Speaker. “Technique du pipeline en planification post mortem,” annual convention, APFF, 2011.
  • Speaker. “Liquidation  de société post mortem – deux stratégies,” APFF symposium, 2011.
  • Speaker. “Liquidation post mortem – stratégie « pipeline,”APFF symposium, 2011.
  • Speaker. “AV Rated for 10 years” award (1999-2009), LexisNexis Martindale-Hubbell, 2010.
  • Speaker. “L'analyse de la possibilité de faire des dons : un service additionnel pour vos clients,” APFF symposium, 2010.
  • Speaker. “Comment réduire la facture fiscale grâce aux stratégies de dons,” APFF symposium, 2009.
  • Speaker. “Aspects pratiques des techniques de don,” APFF symposium, 2008.
  • Speaker. “Table ronde Revenu Québec,” APFF annual convention, 2008.
  • “Income Attribution Update,” annual convention, Society of Trust and Estate Practitioners, 2008.
  • Speaker. “Planification successorale impliquant des bénéficiaires non-résidents,” APFF symposium, 2007.
  • Speaker. “Financement de l’acquisition,” Canadian Tax Foundation, Journée d’études fiscales, 2005.
  • Speaker. “Planification en matière de roulement,” APFF annual convention, 2002.
  • Speaker. “Fiducies en faveur du conjoint,” APFF symposium, 2002.
  • Speaker. “Planification fiscale pour le propriétaire exploitant,” Canadian Tax Foundation, 2001–2002.

Academic Background

  • Trust and Estate Practitioner (TEP), 2002
  • Graduate diploma in tax, McGill University, 1996
  • Member of the Québec Bar, 1983
  • B.A., Carleton University, 1983
  • LL.B., Université de Montréal, 1982