If I buy a property in Birmingham to live in for a short while as my main residence in the UK, how long do I need to live in it before I can buy a second property to become my main home without incurring the higher rate of stamp duty land tax? 

Arthur Weller replies:  

See HMRC’s Stamp Duty Land Tax Manual at SDLTM09812 for the definition of 'main residence' for stamp duty land tax (SDLT) purposes. However, it seems to me that you may have misunderstood the SDLT rules for the extra 3% SDLT surcharge for additional dwellings. If someone sells a qualifying main residence, and buys a new qualifying main residence, they don't pay the extra 3% on the new purchase, even if they own two or more properties after the new purchase.