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

HMRC internal manual

Capital Gains Manual

Share identification rules for corporation tax: section 104 holding: disposals after 30/11/93p

Indexation cannot in general create or increase a loss for disposals on or after 30 November 1993, see CG17700+. The indexation allowance available on a part disposal may have to be reduced. If so, the indexed pool of expenditure is reduced by the full amount of the indexed cost attributable to the disposal. The reduction is not restricted to the amount of indexation actually used in the computation.