Allan has practiced aboriginal law and represented First Nations for over 20 years. Allan has worked extensively in all areas of aboriginal law including aboriginal rights and title, negotiations, litigation,
specific claims, residential schools, taxation and business development, and aboriginal governance. He has represented First Nations and aboriginal people at the Supreme Court of Canada, the British Columbia Court of Appeal, the British Columbia Supreme Court, the Federal Court of Appeal, the Federal Court of Canada, the Tax Court of Canada, the British Columbia Provincial Court and the Indian Claims Commission.
Allan is recognized by the Canadian Legal Lexpert Directory as "Consistently Recommended" and one of the Leading Practitioners in the area of Aboriginal Law. He was voted as one of the leading lawyers in Canada in the area of Aboriginal Law in a peer-reviewed survey published in the inaugural edition of The Best Lawyers in Canada published in June 2006 and every year since.