Beta This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

VAT Valuation Manual

Specific applications: apportionment and valuation of membership benefits: interest-free loans with compulsory and voluntary elements

Sometimes a club will insist that its members make a loan up to a certain level, but give them the option of lending more if they wish. You should treat each of the two loan elements separately as described above - the first part as a compulsory loan and the second part as a voluntary one where applicable.