Only if the applicant has lawful authorization for the second arrangement at that time. Completing one authorized assignment does not automatically authorize a new employer or engagement. Review the scope of the current permission and any required procedure before accepting the second start date. For a Canadian citizen, TN status generally can be requested at a port of entry without a visa stamp; alternatively, a U.S. employer may file Form I-129. TN does not permit U.S. self-employment, relevant ownership interests must be disclosed, and TD dependants may study but may not work.
Plan the handover with both businesses
Identify when the first work ends and what documents or decisions the next work requires. Consider schedule changes if a step remains outstanding. A client’s willingness to delay payment or describe initial work as preparation does not itself resolve the immigration issue.
Create a dated authorization plan showing the earliest document-ready date, requested classification step, admission or petition decision, first paid duty and any later project change. The first review should flag facts that cannot be accelerated, such as a credential record still being issued or an employer contract awaiting signature. Use dated offers, travel history and work schedules to settle the sequence.
Hypothetical example: A Canadian animal scientist is scheduled to begin feed-efficiency research for a Kansas producer on Monday, but the final employer letter is signed Friday after travel is booked. The travel reservation is not permission to begin employment. The decision is whether to postpone the start or use a lawful procedure that matches the actual record; calling the first week orientation does not automatically eliminate the work issue.
Reserve enough time for factual corrections, not just document assembly. The decisive record is the final, truthful employer explanation at the moment the procedure occurs. When a project moves forward, update dates and duties rather than relying on a letter that describes work no longer planned.