CTM49570 | Building societies: application of CT: Capital Gains
From HM Revenue & Customs · Company Taxation Manual
Profits and gains from the loan relationships of a building society will be included in its computation of its CT liability either as part of its Case I income or under Case III.
Chargeable gains on assets that are not loan relationships of the society should be computed according to the provisions of TCGA92/S8. The gains should be included in the computation of profits chargeable to CT.