Admission is granted for up to three years at a time and can be renewed while the professional employment continues, either at a port of entry with a fresh letter or by petition. There is no fixed lifetime maximum, but each renewal is a new assessment of the same facts.
Plan each renewal as if it were the first application
A TN professional is admitted for a period matching the employment, up to three years, and may seek further periods as long as the work remains prearranged professional employment in the listed occupation and the applicant's intent remains temporary. Renewal can be done by presenting an updated employer letter at a port of entry or by an employer petition before the current period expires. Hypothetical example: a Sainte-Brigitte-de-Laval engineer approaching the end of a three-year admission has been promoted into a role that is now mostly project management.
The renewal letter must describe the current duties; if they no longer fit the engineer entry, the renewal can fail even though the original admission was straightforward. For that reason, treat each renewal as a fresh review: reread the entry, update the credential file, and confirm the duties still match. Households should also track the dependants' admission periods, which follow the principal's and must be renewed with them.
Renewal is not automatic and a lapse is a status violation.