FTC 1116 and the new UK "Personal Savings Allowance"

There must now be a strong argument that for most UK resident taxpayers that interest credited after 5 April 2016 is no longer HTKO because the average UK rate on the interest is in most circumstances well below 39.6%.  The effect of this for a US person in the UK is likely to lead to larger amounts of passive basket income with insufficient foreign tax credits.

Also, don't forget NIIT, which raises the highest US tax above 40% - so there's a strong argument that for folks paying UK tax at 40%, interest income would not have been subject to HTKO even before the personal savings allowance was introduced.