Suppose Alice and Bob both own 50% of a rental property each, as tenants in common. Alice gifts 10% to Bob so they now own 40% and 60%. Do Alice or Bob need to declare this gift to any government body?
Alice will need to tell HMRC about the gain if the gift triggers CGT. How does she prove to HMRC that she gave the 10% in the year she gave it so that she can use the correct CGT allowance?
If the gain on 5% is below the threshold, would Alice have avoided CGT if she had made two smaller gifts in consecutive years?