Hi,
If the property was included in probate at the time of inheritance, you should use that figure as the inherited value, when working out capital gains liability.
This is a figure approved by the courts, which is acceptable to HMRC.
Where there was no probate, you can use the market value of the asset at the date of death.
You may need to submit a request for a valualtion (CG34) where there is no formal valuation.
Post transaction valuation checks for Capital Gains (CG34)
Thank you.