HMRC internal manual

Stamp Duty Land Tax Manual

SDLT - higher rates for additional dwellings: What is a dwelling - further information

It will be important in some cases to determine whether a premises consists of one or more than one dwelling.

It is a question of fact whether a purchase consists of one or more than one dwelling. A self-contained part of a building will be a separate dwelling if the residents of that part can live independently of the residents of the rest of the building including independent access and domestic facilities. 

In certain cases a purchase of more than one dwelling will be treated the same as if a single dwelling had been purchased.  This is the case if any of the dwellings purchased are subsidiary dwellings.  A subsidiary dwelling must be within the same building as or in the grounds of another dwelling purchased in the same transaction (the principal dwelling).  The principal dwelling and the garden and grounds attributable to that principal dwelling must be at least two thirds of the value of the land purchased in the transaction.

There can be more than one subsidiary dwelling purchased at the same time as a principal dwelling, but the principal dwelling must always be at least two thirds of the transaction value.

Where a principal dwelling is purchased and all the other dwellings purchased are subsidiary dwellings, the tests for whether the transaction is a higher rates transaction are applied as if there was only one dwelling purchased. If the purchase of a principal dwelling is a first property purchase or a replacement of a main residence the higher rates will not apply. 

Multiple dwellings relief may be claimed where there are separate dwellings.