Income is calculated using the surplus amount of rental income after deducting all costs of property management and mortgage interest payments. 



Please note:


Investment income from land and property can only be used for self-financing portfolios (A portfolio is classed as self-financing where rental income is greater than 145% of mortgage payments on an interest only basis at 5.5%)
Where the BTLs are Capital and Interest, the income can be used within the assessment but the full mortgage cost must be taken as a deduction.