Have counsel assess whether the present facts support the chosen procedure before filing. If the employment commitment remains unresolved, a later funding expectation does not fix an inaccurate current statement. Coordinate evidence readiness with the institution rather than filing to meet an internal grant calendar.
Use a decision date for the appointment
Agree when the institution will confirm, revise or withdraw the offered start. That checkpoint gives the household a practical basis for its next decision without promising an immigration result. If the job changes after preparation, review the updated facts before relying on the original documents.
Two routes exist and they fail differently, which is why the choice belongs before the calendar. A Canadian citizen may generally request TN at a Class A port of entry or a pre-clearance location, where the assessment happens in one sitting and the applicant is present for it. Alternatively the employer may file Form I-129, which separates preparation from the decision and leaves room to answer questions on paper.
Hypothetical example: a dietitian books flights around a port-of-entry request while the institution is still deciding whether the post exists, and arrives holding an offer letter that no longer describes the arrangement. Ask counsel which route suits facts that are still moving. Whichever is chosen, a change of employer generally requires a new request or a new petition, so the entity named at the outset is not a detail to settle later.