Thanks. Maybe I'm getting confused between CGT and ADS...Re. "the principle residence" rules....Scotland I see. Equivalent to second home stamp duty, but at 4% instead of 3%.
Are you sure that your parents would get hit for this. I'm sure that wouldn't be intended, but obviously it depends on what the law says. I found https://www.revenue.scot/land-buildings-transaction-tax/guidance/lbtt-legislation-guidance/lbtt10001-lbtt-additional-dwelling
Which says:. "The ADS applies to most purchases of additional dwellings by individuals in Scotland where, at the end of the day that is the effective date of the transaction, a buyer owns two or more dwellings and is not replacing their main residence. It also applies to most purchases of dwellings by non-natural persons (e.g. companies, partnerships) in Scotland."
I feel that you should seek legal advice or at least ask revenue Scotland what the position would be in these circumstances.