This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Oil Taxation Manual

Corporation Tax Ring Fence: Definitions of Ring Fence Income and Ring Fence Profits

CTA10\S275, CTA10\S276

CTA10\S275 defines ring fence income as income arising from oil extraction activities or oil rights.

CTA10\S276 defines ring fence profits as ring fence income plus the aggregate gain, if any, computed in accordance with TCGA92\S197(3).