TL;DR: A B-1 visitor can install, service or repair equipment bought from a company outside the U.S., or train U.S. workers to do so, if the sales contract requires the seller to provide that service, the visitor has unique knowledge essential to it, and gets no U.S. pay. Building or construction work is excluded. ESTA allows the same activities, but stays are limited to 90 days with no extension.
The rule: 9 FAM 402.2-5(E)(1)
On factory projects the same question comes up again and again: “Can the equipment maker’s specialists just come on ESTA?” Sometimes yes, sometimes a clear no, and the difference is in the contract, the actual tasks and who pays.
Under the State Department’s Foreign Affairs Manual, 9 FAM 402.2, a B-1 may fit someone coming to install, service or repair commercial or industrial equipment purchased from a company outside the U.S., or to train U.S. workers to do it. Three conditions apply:
- The contract requires it. The contract of sale must specifically require the seller to provide the services or training.
- Unique knowledge. The visitor must have unique knowledge essential to the seller’s contractual obligation.
- No U.S. pay. The visitor must receive no remuneration from a U.S. source.
The limit that matters most on job sites: these provisions don’t apply to building or construction work, on-site or in-plant. The exception is supervising or training workers who do that work, without doing it yourself.
The B-1 fact sheet also describes a “specialized trainer” category under 9 FAM 402.2-5(E)(2) for training U.S. workers on proprietary know-how for foreign-sourced equipment in support of a “qualifying project,” with visas annotated “B-1 SPECIALIZED TRAINER.” The fact sheet doesn’t define “qualifying project,” so confirm with counsel before anyone books flights.
What B-1 can and cannot cover
Both the State Department and the U.S. Embassy Seoul’s B-1 fact sheet (PDF) say B-1 isn’t for employment or labor. Final calls belong to the consular officer and CBP.
| Activity | B-1 / ESTA? | Why (per State Dept guidance) |
|---|---|---|
| Installing or repairing a machine bought from an overseas seller, when the sales contract requires the seller to do it | May qualify | 9 FAM 402.2-5(E)(1), if the unique-knowledge and no-U.S.-pay conditions are met |
| Training U.S. workers to run or service that equipment | May qualify | Same provision, or the specialized trainer category |
| Supervising or training a construction crew without doing the work | May qualify | Stated exception to the construction exclusion |
| Building or construction work, on-site or in-plant | No | Expressly excluded from the provision |
| Meetings, contract negotiation, conferences | Generally yes | Listed allowable business activities |
| Being paid a salary by the U.S. company for the work | No | No U.S.-source salary; reasonable incidental expenses only |
| Filling a regular production or labor role | No | B-1 is not for employment or labor |
Expenses vs salary. Under 9 FAM 402.2-5(F)(1), a U.S. source may reimburse reasonable travel and living costs such as meals, lodging and laundry. A U.S. salary is a different thing. If your project uses per diem, ask counsel how it fits.
ESTA limits
South Korea is a Visa Waiver Program country, and ESTA admission allows the same activities as a B-1 visa. The Visa Waiver Program page adds firm limits:
- 90 days or less, with no extension and no change of status inside the U.S.
- ESTA before boarding, and approval doesn’t guarantee entry. CBP decides at the port of entry.
- A recent visa refusal can lead to ESTA denial or extra review.
If commissioning could run past 90 days or the scope is unclear, a B-1 visa interview lets the consular officer review the plan before travel. The B visa fee is listed at $185.
“Can they cancel my ESTA after one long site stay?”
This is the fear engineers raise most before a U.S. trip, especially after the September 2025 federal enforcement operation at a battery plant site in Georgia. The official position is clearer than the rumors: the B-1 fact sheet allows contract-required equipment work on ESTA, but not construction work or a U.S. salary. Not legal advice; every case is different.
- Is installation written into the sales contract?
- Will anyone on this trip do hands-on construction work?
- Who pays my salary: my employer abroad or a U.S. entity?
Official U.S.-Korea steps since 2025
The two governments have met through a Business Travel and Visa Working Group. Here’s only what official U.S. pages confirm:
- October 2025: U.S. Embassy Seoul published its B-1 allowable uses fact sheet.
- Oct. 21, 2025: the second Working Group meeting stressed lawful travel of Korean workers who support investment and train American workers (State Dept).
- By Jan. 2026: the Embassy launched the Korean Investment and Travel Desk (KIT desk announcement). I couldn’t confirm its exact procedures, so check the announcement directly.
- Jan. 28, 2026: the third meeting in Seoul welcomed the KIT desk (Embassy media note).
“Is it still a gray zone after Georgia?”
Here’s what is in writing now. The Embassy’s January 28, 2026 fact sheet repeats that installation, servicing and repair are allowed when the sales contract specifically requires the seller to provide them and the traveler has essential unique knowledge. If an activity isn’t clearly covered, it says to apply for a more appropriate visa. Before you go, ask for the contract clause covering your work and carry a copy.
A practical compliance checklist
These are habits that keep projects calm, not official forms. Review them with counsel.
- Read the sales contract. If it doesn’t require the seller to install, service or train, (E)(1) isn’t the right fit.
- Write the scope down. Separate each visitor’s equipment tasks from building or construction tasks.
- Check pay flows. Salary from the foreign employer; U.S. payments only for reasonable incidental expenses.
- Plan the calendar. If ESTA could run past 90 days, plan for a visa early.
- Match the English contract. Contracts on Korean-affiliated projects are often drafted in Korean first. Make sure the English version says the same thing.
- Use a work visa when it’s work. Ongoing hands-on production or a regular job belongs in a proper category such as L-1 or E-2.
Training U.S. workers is part of the point of these provisions, and local technicians often get hired to take over from visiting specialists.
FAQ
Can I install equipment on ESTA instead of a B-1 visa?
ESTA allows the same activities as a B-1 visa, but it’s limited to 90 days with no extension or change of status, and CBP decides admission at the border.
Can a B-1 visitor do construction work at a plant?
No. Building or construction work is excluded, on-site or in-plant. Supervising or training construction workers, without doing the work, is the stated exception.
What if the job is longer or more hands-on?
Then it likely needs a work visa. I cover the options in my visa sponsorship guide.
Sources, checked October 2026: 9 FAM 402.2, State Dept B-1 fact sheet, U.S. Embassy Seoul B-1 fact sheet, Visa Waiver Program.
