CG14781 - Assets disposed of: series of transactions: just and reasonable
Any apportionment you make under Section 52(4) has to be on a just and reasonable basis. That phrase has not been defined but we take it to mean by reference to the facts of the case. Where you are dealing with the disposal of a number of assets as part of one bargain, you may be able to begin the apportionment by obtaining an informal valuation of one or more of the assets, see CG14783.
The Corporate Intangibles Research and Development Manual provides further guidance on the meaning of a “just and reasonable” apportionment of the valuation of intangible assets within that regime, see CIRD49010 and CIRD49020. Also see the examples at CIRD49030.