Hello, I am Keith, one of the experts on Just Answer, and pleased to be able to help you with your question.
As you have taken a mortgage to acquire your BTL then the interest element only is a normal charge against rental income. I would be inclined to so claim the interest. It is, however, only allowable at the basic rate of taxation. Also the taxation is on turnover. There used to be an allowance of 10% for wear and tear, but this is now confined to actual expenditure. These rules come into force 2017 to 2020 and you can read full details of the effects of the Chancellor's unexpected clamp down here:
I am so sorry to have to rain on your parade. The media comment is that it effectively means an end to BTL.
Delighted to have been of assistance.
Thank you for your support.