The value of voluntary activity in the UK for 2012 is estimated to be £23.9 billion, approximately 1.5% of GDP. This paper discusses the methodology and the assumptions used in this estimation. It is part of the Household Satellite Account, which attribute monetary values to household production activities that are not included in the National Accounts. These estimates are an update of the voluntary activity estimates published by the Office for National Statistics in 2002 for the year 2000. This paper also provides possible options for valuing the intervening years.