Consolidated groups often aim to form from the beginning of an income year to avoid the need for part-year returns. If this is the intention ensure that the date notified as the date of consolidation is the first day of the income year (1 July for June balancers).
If, for example, a group forms on 30 June, the head company will need to include its own income and expenses up to and including 29 June, together with the joining subsidiaries' income and expenses for the one day of 30 June. The subsidiaries will need to include in their returns income and expenses up to and including 29 June. In the balance sheet labels at item 8 the head company will need to record amounts that show the financial position of the group at 30 June while the joining subsidiaries will need to record amounts that show their financial position at 29 June.