Merrill is a member of the law firm of Donovan & Company. He received his undergraduate degree from York University, Toronto, Ontario, his law degree from Queen's University, Kingston, Ontario and was
called to the British Columbia Bar in 1975 and to the Northwest Territories Bar in 2001.
From 1974 to 2001 he was in private practice in Vancouver primarily in the field of taxation law. He has lectured in tax law including seminars presented in connection with Simon Fraser University, The University of British Columbia, Insight, The Canadian Institute, and the Canadian Tax Foundation.
By 2005, when he joined Donovan & Co., all of Merrill's practice became devoted to aboriginal communities with respect to tax, corporate, trust and other structuring issues related to their community assets. He lectures on these subjects for the Canadian Bar Association.