IHTM25271 | Business relief: Investment businesses: Property letting
From HM Revenue & Customs · Inheritance Tax Manual
You should investigate whether the rule excluding investment businesses (IHTM25261) from business relief applies if the business involves a caravan site, letting of furnished accommodation, a furnished holiday letting, letting commercial premises or other letting activities. There may be a wide range of activities within any of these headings.
The two tests that need to be applied in these cases are:
whether the activities carried on constitute a business for the purposes of IHTA84/S105 (1)(a);
if they do, is relief precluded because that business was one of ‘wholly or mainly holding investments’, IHTA84/S105 (3).