The H-1B visa program generally allows a foreign employee to work for a specific sponsoring American employer. As is true in many employment situations, the location of work can change. USCIS has published a policy memorandum making clear that USCIS may request detailed documentation to ensure a legitimate employer-employee relationship is maintained while an employee is working at a third-party worksite.
In publishing this policy, USCIS clarifies existing regulatory requirements relating to H-1B petitions filed for workers who will be employed at one or more third-party worksites. This policy memorandum makes clear that employers must provide contracts and itineraries for employees who will work at a third-party location.
The guidance, effective Feb. 22, 2018, explains that, in order for an H-1B petition involving a third-party worksite to be approved, the petitioner must show by a preponderance of evidence that, among other things:
USCIS Link: https://www.uscis.gov/news/news-releases/uscis-strengthens-protections-combat-h-1b-abuses