Where in a tax year:
then the securities income accruing during that part of the
relevant period is apportioned on a just and reasonable basis
between the UK and non-UK duties. That proportion of the securities
income which is attributed to the non-UK duties is then treated as
FSI, and is therefore only taxable if remitted to the UK.
In the normal case, where the duties performed in the UK and
overseas are broadly similar and there are no other special
factors, HMRC would accept apportionment by reference to the number
of workdays spent in each location as giving a just and reasonable
result.