Stamp duty refund

Hello. In 2023 I was living in a flat which I owned jointly with my sibling (I have a 50% share, as tenant in common with my sibling - he owns the other 50%). I then purchased a new property, and moved into this new property - it is now my main residence. At the time of this purchase I still owned the flat I own with my sibling, so I had to pay the additional rate of Stamp Duty Land Tax on the new property I purchased. If I gift my 50% share of my flat to my sibling (ie. for no cost) within 3 years of the purchase of my new property, would I qualify for a refund on the additional rate of Stamp Duty Land Tax which I paid for my new property?

Hi,
We cannot advise on stamp duty matters as they are not part of income tax.  
Please have a look at the guidance at Stamp Duty Land Tax
Thank you.