Valuation Office Agency
Do not make requests for your own personal information or seek to correspond about your own property tax affairs via WhatDoTheyKnow.  


The Valuation Office Agency (VOA) is a an executive agency of HMRC  and gives the government the valuations and property advice needed to support taxation and benefits


If you are seeking the sale price of property see the Land Registry (many services make data from the Land Registry available; some place data freely online).


You can view property valuation details via the Valuation Office Agency's online service.