The qualifying employment and other L-1B conditions still need to be established.
Assess duration in its proper role
A brief project does not create a new knowledge or service test. Identify the actual duties and the continuous qualifying foreign year within the relevant three-year period.
Test every statutory element even when the assignment lasts only days. L-1B requires one continuous year of qualifying foreign employment within the preceding three years and service for a parent, branch, subsidiary, or affiliate. For a non-new office, the qualifying organization must be doing business as an employer in the United States and at least one other country; a new office instead must meet the special commencement requirements. The U.S. position must require special knowledge of the company's products, services, research, equipment, techniques, management or other interests, or advanced knowledge of its processes and procedures, rather than ordinary occupational skill. Map the proposed tasks to that knowledge and record any earlier L periods against the five-year maximum. Where work occurs at an unaffiliated customer site, the petitioner must retain control and the placement cannot be labour-for-hire. A new office receives only a one-year initial period. The common mistake is treating commercial brevity as an exemption from evidence.
Hypothetical example: an Orford furniture-finishing chemist is needed for four days to diagnose colour instability in a proprietary coating line. Her employer should document her continuous Canadian service, the affiliate relationship, internal formulation training, prior troubleshooting, and the precise diagnostics she will perform. If the customer assigns her shifts and substitutes ordinary laboratory work, the control and specialized-knowledge theories weaken. A four-day itinerary helps define scope, but it does not waive the foreign year or turn general chemistry expertise into company-specific knowledge.