Residential SDLT rates 

Rates for a single property.  

An additional 5% on top of SDLT rates is payable if the purchase will mean you own more than one residential property, unless the property replaces your main residence and your previous main residence is sold within 36 months of completing your new purchase. For first time buyers, no SDLT is payable up to £300,000 and SDLT is 5% on the £300,001 to £500,000 portion.
Chart: S&WSource: Gov.uk