Leaving aside the CGT issue which presumably your sister will take advice on, if the house sells for 300,000, you will therefore be gifted approximately 100k from your sister. Obviously costs and expenses of the sale will result in a slightly smaller net figure, but just as an example, take it that the figure is 100K. You are entitled to take only approx €47,815 free of tax from your sister ( assuming no prior gifts from another source or indeed from this sister). The balance is taxable at 20%. The first €3000 taken in any year is free of tax, therefore you could take the full 47,815 first and then a further 3K per year free of tax.