You might need a retrospective valuation for 2 main reasons:
Capital Gains Tax
When you sell, transfer or dispose of a property that is not your main home you have to pay Capital Gains Tax to the HMRC it if it has increased in value since you acquired it.
Capital Gains Tax valuations are often retrospective because the surveyor has to establish the value either at the purchase date or where the property was purchased before 1982.
From 5 April 2015, non-UK resident individuals became liable for non-resident Capital Gains Tax (NRCGT) on the disposal of residential properties situated in the UK.
More information about our Capital Gains Tax valuations can be found here
Inheritance Tax (Probate)
An Inheritance Tax valuation for the purposes of Probate is a type of valuation undertaken by an RICS qualified chartered surveyor to determine how much tax must be paid to the HMRC on an estate before it passes on to the beneficiaries.
Inheritance Tax valuations are sometimes retrospective because it can take a long time for Probate to be granted.
More information about our Inheritance Tax for Probate valuations can be found here
Further reasons for Retrospective Valuations
In addition to Capital Gains Tax and Inheritance Tax you might need a Retrospective Valuation for Right to Buy and ATED (Annual Tax on Enveloped Dwelling).