Hi,
Yes, you are entitled to claim an apportionment of your mortgage interest and household bills covering the days your property is let.
To claim residential finance costs, you would complete a self-assessment tax return and a UK Property page (SA105), and the proportion of residential finance costs would be noted at box 44.
Our systems will automatically calculate the tax relief due at 20%.
Please complete any other supplementary pages you need to complete to ensure you declare all your income and claim your reliefs.
However, you may qualify for tax-free allowance (£1000) on property and trading income.
If that is the case, you may not be required to file a tax return.
Please refer to Tax-free allowances on property and trading income:
PIM4410
Thankyou.