IHTM14164 - Lifetime transfers: schemes to exploit annual exemption: transfer of share quantified by loss in value
The deed transfers as much of a share of a property so that the retained share is equal in value to the value of the whole minus, say, £3,000.
This effects a transfer equal in value to £3,000. The calculation of the retained share is an asset of the estate and you will need to refer its valuation to the Valuation Office (IHTM23002).
If you come across this point refer the matter to Technical.