CTM80320 | Groups: group relief: meaning of non-UK profits
From HM Revenue & Customs · Company Taxation Manual
For the purposes of group relief in respect of the losses of permanent establishments and determining whether tax relief is available or has been given against non-UK profts in an overseas jurisdiction (CTM80310) ‘non-UK profits’ means any amount:
which is, or is taken into account in computing, profits, income or gains on which foreign tax is charged, and
which is not, or is not taken into account in computing, UK profits chargeable to CT for any accounting period.
Note that profits of the UK permanent establishment assessed to tax in foreign jurisdiction are not non-UK profits for this purpose.