I have a friend who owns 5 horses. Two of these he uses for showjumping. His wife owns a horse which she brings and shows at agri shows etc. His daughter owns a horse which she rides. Sometimes he sells horses. As the profit he makes from these horse sales can be significant at what point do the sales become taxable and cease to be a by-product of his hobby. He maintains that it is still a hobby even though he could have made €20k from sales last year.Likewise with the sale of motor cars. I have a friend who buys old cars, does them up, holds them for a while and then may sell them. When does the hobby stop and when does the trade start?