The business must have qualifying treaty nationality
The individual applicant must have the relevant treaty nationality, and the business must also meet the treaty-country nationality requirements.
Where the applicant is an employee rather than the principal treaty trader, the employer and employee generally need to share the same treaty nationality.
There must be real international trade
E-1 trade requires an actual international exchange between the treaty country and the United States.
It is not limited to physical products. Qualifying trade can include services and technology as well as goods. State Department guidance identifies examples including banking, insurance, transportation, tourism and communications, while making clear that the list is not exhaustive.
This is important for UK consulting, technology, engineering, professional-services and other service businesses that may incorrectly assume E-1 is only available to importers and exporters of physical goods.
The trade must be substantial
There is no single revenue figure or fixed number of transactions that automatically makes trade “substantial.”
The State Department focuses on the continuing flow of trade and normally expects numerous transactions over time. Both the number and monetary value of transactions can be relevant. A pattern of smaller transactions may still qualify, while one very large isolated transaction will not necessarily establish the required continuing trade.
This is why the question is whether the evidence shows a genuine, established and continuing course of UK-US trade.