Secondment vs. transfer: a field guide for HR

Insights · Patrick Smith, Attorney at Law · September 13, 2026

The short answer: the United States has no general equivalent of an EU posting. Whether an employee stays on the home payroll matters far less than what they will actually do in the US and which company they will do it for. Productive work in the US generally requires a work-authorized status, most often L-1, E, or H-1B, even for short assignments.

Why the vocabulary breaks down

Inside Europe, mobility teams work with the Posted Workers Directive, A1 certificates, and the intra-corporate transfer (ICT) permit. Those frameworks are built around where the employee is paid and insured. US immigration law asks different questions: what activity will the person perform on US soil, who benefits from it, and what relationship exists between the foreign employer and the US entity.

Short trips: the business visitor line

Employees traveling on the Visa Waiver Program (ESTA) or a B-1 visa can attend meetings, negotiate contracts, consult with colleagues, and attend conferences. They generally cannot perform hands-on work, fill a role in the US team, or deliver services to a US client. The most common compliance mistake in European mobility programs is treating a two-month project as a business trip because it is short. Duration is not the test; the activity is.

How EU terms map to US categories

• Intra-corporate transfer (EU ICT permit) maps most closely to the L-1. The employee needs one continuous year with a related company abroad within the last three years and must come to work for a parent, subsidiary, branch, or affiliate in an executive, managerial, or specialized-knowledge role.
• Secondment to a US subsidiary or branch usually runs through the L-1 as well, or through E-1/E-2 status when the company and employee share a treaty nationality.
• Local hire or contract for a US client generally needs its own route, often the H-1B for degreed specialists, with its annual registration calendar.
• Opening the first US office fits the new-office L-1 or an E-2 investment, each with its own evidence of a real, funded operation.

Payroll, social security, and tax

An L-1 employee can often remain on the home-country payroll, which surprises many HR teams. Social security is a separate question: the United States has totalization agreements with many European countries that can let an assignee stay in the home system for a limited period. Tax residence is separate again. These are coordination points for payroll and tax advisers, and the immigration plan should be built alongside them rather than after.

A practical sequence

Start with the activity and the corporate relationship, then nationality, then timing against any lottery calendar, then family needs. Settling those four points before the assignment letter is signed keeps the widest range of options open.