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HMRC internal manual

Capital Gains Manual

Share reorganisations: apportionment of cost: main rule

In most cases the market value of the part disposed of will be the same as the consideration received. In practice because the difference is likely to be small you can use the consideration received rather than the amount of market value. This makes the formula identical to that in TCGA92/S42.

Where the new holding only includes shares or securities of one class you can use the short cut method described in CG51575 and make the apportionment by reference to the number of shares or securities sold.  This will apply where, say, there is a bonus issue of shares or securities of the same class and the normal share pooling rules do not apply.  Share pooling did not apply for CGT purposes for shares between 1998 and 2008 and there continue to be a number of situations where pooling does not apply.