They can... but a few things to keep in mind: 1) A start-up for a "few" employees is not really economical for many service providers. They should be prepared for "above average" costs; 2) Assets need to be held within the jurisdiction of U.S. District Courts. That generally means the situs of the trust is in the U.S. which generally means a U.S. based trustee; 3) Choice of plan sponsor might be of concern as well. The one's I've done had a "U.S." subsidiary (a corporation based in the U.S.) which employs the U.S. based employees. That makes it easy - make the U.S. sub the sponsor. If not (and just having an EIN doesn't mean they do), there are some interesting legal and fiduciary issues that may be impacted by Canadian law that the company should investigate with international counsel (one versed in both Canadian law and ERISA); finally, the plan should be drafted very carefully to ensure only the intended employees are included - especially if people bounce across the border occasionally.