The professional needs the relevant authorization before beginning the proposed U.S. employment. A drafted letter, booked trip, or employer urgency does not create permission by itself.
Set the first workday after authorization
Schedule the employer's letter, credential collection, and any applicable petition or inspection step before the first day of U.S. duties. Clarify what tasks will occur while preparation is underway and where they will be performed.
Do not use a visitor description to start the same professional work before TN authorization is obtained. If the employer changes duties, location, or timing, check whether the new arrangement needs a different analysis rather than assuming the original record automatically covers it. Work backward from the intended lawful start rather than from a desired flight or business launch.
Include time for records, translations, company decisions, government processing, visa steps where applicable, and unexpected requests for evidence. Do not begin restricted U.S. activity because paperwork is being drafted or a future filing is contemplated.
Recheck instructions near the filing or travel date because procedures and availability can change. Keep a contemporaneous record of the decision and the facts used to reach it. When a document is unavailable, identify the reason and consider whether another primary record can establish the point without creating a contradiction.
A later change in role, ownership, family circumstances, or planned activity may require a fresh review. Clear disclosure is more useful than an attempt to make facts appear simpler than they are.