US Company w/ a 401k that allows rollovers by participants from prior employer plans recently hired X. X previously lived and worked in the United Kingdom for a UK company and particpated in that company's "qualified plan." X would like to rollover his plan balance from the UK plan to the US company 401k. (I do not have details of UK plan re: distributions/rollovers but assume that is not a deal breaker) Is there a "simple" answer or useful resource available on this situation??? Would the answer be any different if X established an IRA to receive the UK rollover?? THANKS for any guidance.

Review the new US-UK tax treaty.

http://www.irs.gov/businesses/corporations...d=96739,00.html

In order for the distribution to be eligible for a rollover the UK plan would have to be a qualified plan under US law, e.g., a domestic trust established under state law. If X is a US taxpayer, the distribution would be subject to US taxation since the US-UK treaty generally provides for each country to tax its nationals and not tax the other's nationals.