My husband and I have owned a home for over twenty-five years, and it is our main residence. We file our taxes from there and all utilities are paid from there; we also vote from there.  We rent a property in the countryside because our children's school is too far to commute, and most weekends and holidays we are at home. In the last few years, although not last year, we have periodically rented out the house through Airbnb. Our current mortgage is buy-to-let (BTL). It is our only home. Will we be liable for capital gain tax when we sell, even though it is our only property? 

Arthur Weller replies:  

HMRC’s Capital Gains manual at CG64500 states that where someone owns one house but also rents another property and lives concurrently in both, they can make an election that the house they own is their main residence and therefore, eligible for principal private residence relief, even if the election is made after the date it should have been made.