Section 13AB and this Schedule apply in relation to an accounting period of a company in which it ceases to be a member of the group as if there were two accounting periods, one ending immediately before the company ceases to be a member of the group and the other consisting of the remainder of the period.

For this purpose a company ceases to be in a group if it and another company cease to be in the same group, whether as a result it is no longer in a group, becomes a member of another group or continues to be in the same group as one or more other companies.