About 20 years ago I lent my parents £50,000, which was half the price of a house, so they could buy a house. My name does not appear on the title deeds etc. The agreement was that when the house was sold, I would receive my money back plus half of the increase in value of the property. I have now received £110,000. Would you treat the £60,000 as capital gain or interest? 

Arthur Weller replies: 

I would treat the £60,000 as interest. You did not own, either legally or beneficially, any part of the house. This is called 'rolled up interest'. Dependent on the actual terms of the loan, frequently tax is only due on rolled up interest when it is actually paid, see HMRC’s Savings and Investment manual at SAIM9100.