I have sold an option to buy my house (my residence) to a developer for £20,000. This gives the developer the option to buy my house for £200,000 within the next year. If he goes ahead with the purchase, he will give me the remaining £180,000. If he does not go ahead, I keep the £20,000. Would the option I have sold still be elegible for private residence relief, even if he does not eventually buy the property? If not, how would it be taxed?