Founded in 1993, TaxMentor has been providing monthly insights into the tax news affecting Owner-Managers for 10 years now. Headed up by Editor-in-Chief and the Principal of TaxMentor, Bill Cooper, TaxMentor brings a unique insight into tax matters that only a Tax Lawyer who is also an Accountant can deliver.

Who We Are

Editor in Chief

William (Bill) Cooper, CGA, LLB

William (Bill) Cooper, CGA, LLB

With over 40 years of tax and financial experience starting as a financial analyst and controller with a multi-national forest products company and the last 30 of those years as a tax lawyer, Bill has worked on a wide array of tax driven business problems ranging from estate plans for the owner/manager to large multi-national cross-border corporate restructurings. Bill has also been a tax lecturer at the University level as well as working as an advisor at the most senior levels of Canada Revenue Agency and the Department of Finance in Ottawa. For more information see the Boughton Law Corporation website where Bill is associate tax counsel and the co-founder of Meritas Canada Tax, an affiliation of some 30 tax and estates lawyers practicing from coast-to-coast – a great resource including some of the brightest tax minds in the country that meet monthly to share their tax knowledge.

Associate Editors and Monthly Webinar Leaders

Karen O’Neill, BSc, TEP, CA

Karen O'Neill, BSc, TEP, CA

Karen is an experienced high net worth income tax specialist focused on estate and trust planning, income splitting, reducing double taxation on death, post-mortem planning, minimizing income tax and probate fees on death, and reviewing wills from an income tax perspective. She is involved in all aspects of the tax planning process (discussion, planning, implementation and reporting) with clients and their professionals using a team-based approach. Her previous experience includes working for PwC where she managed high net worth tax projects to completion working with clients and their advisors to achieve income tax planning objectives. Her projects included estate and trust planning, minimizing tax on death, planning to eliminate double taxation on death, meeting charitable giving goals, family trusts, will review from an income tax perspective, capital gains planning, personal tax, trust and corporate tax review and compliance. You can contact her directly at

Moon Mah, CPA, CGA, LLB

Moon Mah, CGA, LLB

As both a lawyer and a CPA, CGA, Moon has the training necessary to assist business owners with respect to all of their tax planning and tax appeal needs. Prior to his legal career, Moon worked in the audit division of Canada Revenue Agency. While practicing tax and business law at one of Winnipeg’s leading law firms, Moon also taught taxation at the Asper School of Business at the University of Manitoba. Now with Boughton Law’s Tax Department, Moon can be reached directly by e-mail at

Deborah E. Graystone, BSc, TEP, CPA, CGA

Deborah E. Graystone, BSc, TEP, CGA

Deborah is a tax partner in the Vancouver office of BDO, one of the world’s largest international accounting firms. Deborah has over 25 years of public practice experience in personal, corporate and estate taxation. Her focus includes corporate reorganizations, mergers and acquisitions, structuring real estate development projects, partnership issues, and business succession. She is also a frequent lecturer and author on complex taxation matter. Most importantly, as one of the leaders in BDO Canada’s National Tax Group, Deborah brings a wealth of tax information and insight to our monthly Webinars that only someone with access to a National Tax Group of a major Audit Firm can offer. See the BDO website for further details.


SHEILA LEIGH, Paralegal & TaxMentor Coordinator

SHEILA LEIGH, Paralegal & TaxMentor Coordinator

Sheila is a senior tax paralegal with over 25 years in corporate law and the last 16 years specializing in tax and estates from the reorganization and planning perspective. Currently with Boughton Law Corporation’s Tax Department she has also acted as Coordinator for TaxMentor for the past ten years.