FAQ - ANSWER

Can I rollover my U.S. 401k into a U.K. pension scheme when I return home to the U.K.?

Answer: A U.S. 401k plan is not a "qualified" plan in the U.K. therefore a 401k can't generally be rolled into some type of U.K. pension scheme. But, this is not a "do-it-yourself" area of pension law and you should check with an attorney that knows this area and the treaties involved.

Here is some background reading that will be of interest:

Pensions and Stock Options under the New U.S. -- U.K. Tax Treaty

Treasury Issues Press Release Summarizing U.S.-U.K. Tax Treaty

IRS Publication 515, Withholding of Tax on Nonresident Aliens and Foreign Corporations, includes a list of tax treaties and several other tables of tax treaty information.