INTM254180 | Controlled Foreign Companies: legislation - introduction and outline: Requirements of the legislation
From HM Revenue & Customs · International Manual
The general scheme of the legislation requires:
a computation of the profits (exclusive of capital gains) of a controlled foreign company for an accounting period, broadly on the lines of Corporation Tax profits,
an apportionment of the profits among those with an interest in the company, then
self assessment to tax by all United Kingdom companies to which 25% or more of the profits have fallen to be apportioned. (Amounts apportioned to associates are taken into account in calculating whether the 25% threshold is passed, but not in calculating the amount of tax due.)