After working at the law firm of his father and uncle, Louis Guertin established Guertin Law in 1987 with the help of his wife, Julie. Their daughter, Natalie, joined in 2009, followed by Michèle Poirier in 2016.

Since 2016, Natalie and Michèle have collaborated to advance the practice. In 2021, they partnered to take over the firm and rebranded as Guertin Poirier Avocates/Lawyers. They proudly continue to serve Ottawa’s English- and French-speaking communities.