The applicant needs a lawful basis permitting the actual work before it begins. An unfinished proposal or pending preparation is not authorization. Review whether the employment and evidence are sufficiently established for the applicable process and adjust the schedule if necessary.
Keep preparation distinct from delivery
Identify what the applicant intends to do in the United States and under which status. Do not call productive services an introductory meeting merely to begin early. The client’s deadline cannot replace the required immigration step.
Work backward from the date productive services are needed. First settle the US recipient, duties, remuneration, and duration, and obtain an employer letter or contract documenting the offer; then confirm Canadian or Mexican citizenship, the correct USMCA profession, and that profession’s credential rule. TN must involve prearranged professional work and cannot authorize US self-employment. Once the record is stable, a Canadian outside the United States may request TN classification at a port of entry or the US employer may first file Form I-129; after approval of an advance petition, the Canadian must still seek admission. Keep contract discussions, interviews, and permissible meetings distinct from producing client work. The common timing failure is allowing a commercial milestone to turn drafting or “orientation” into uncompensated delivery before authorization, on the theory that a later signature or approval will relate backward.
Hypothetical example: A Sherbrooke soil scientist is asked to collect and interpret samples for an American environmental firm while final payment clauses remain open. She may finish negotiations and prepare her credential evidence from Canada, but should not begin field analysis in the United States merely because the sampling season has started. Her schedule should leave the first productive day conditional on a documented prearranged role and TN admission, including after any applicable advance petition approval.