The three things that must all be true
EB-1C looks simple and is not. It requires a qualifying relationship between the two companies — parent, subsidiary, affiliate or branch — plus one year of qualifying employment abroad within the three years before the petition, plus a U.S. entity that has been doing business for at least a year.
The word doing carries weight. A U.S. entity that exists on paper, with a registered address and no operations, does not meet it.
Managerial is a legal term, not a job title
This is where most EB-1C denials come from. USCIS does not care what the business card says. It asks whether the person primarily manages the organization or a function, supervises professional staff, and has authority over hiring and firing — or, for executives, whether they direct the management of the organization and set goals with wide latitude in decision-making.
Someone who runs a small team but spends most of their time doing the technical work is, for this category, not a manager. Organizational charts, headcount and a description of who does the non-managerial work are what settle it.