For the tax year 6 April 2018 to 5 April 2019 the allowable costs of getting a loan or alternativefinance to buy a residential property that is let ,plus any interest on those loans and alternativefinance agreements is restricted to 50% of the costs.
50% of the costs should be shown in box 17 of the SA106, the remaining 50% should be shown as below
Click on the Foreign Income Page
Select Land and Property Abroad
Fill in all required Information about the property.
Enter the Residential Finance Costs i.e 50% of the mortgage interest paid